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  1. /*
  2. *   Copyright (C) 2017 Daniel Morales
  3. *
  4. *   This program is free software: you can redistribute it and/or modify
  5. *   it under the terms of the GNU General Public License as published by
  6. *   the Free Software Foundation, either version 3 of the License, or
  7. *   any later version.
  8. *
  9. *   This program is distributed in the hope that it will be useful,
  10. *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12. *   GNU General Public License for more details.
  13. *
  14. *   You should have received a copy of the GNU General Public License
  15. *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16. */
  17.  
  18. /*** Include section ***/
  19.  
  20. // We add them above our includes, because the header
  21. // files we are including use the macros to decide what
  22. // features to expose. These macros remove some compilation
  23. // warnings. See
  24. // https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html
  25. // for more info.
  26. #define _DEFAULT_SOURCE
  27. #define _BSD_SOURCE
  28. #define _GNU_SOURCE
  29.  
  30. #include <ctype.h>
  31. #include <errno.h>
  32. #include <fcntl.h>
  33. #include <signal.h>
  34. #include <stdio.h>
  35. #include <stdarg.h>
  36. #include <stdlib.h>
  37. #include <string.h>
  38. #include <sys/ioctl.h>
  39. #include <sys/types.h>
  40. #include <termios.h>
  41. #include <time.h>
  42. #include <unistd.h>
  43.  
  44. /*** Define section ***/
  45.  
  46. // This mimics the Ctrl + whatever behavior, setting the
  47. // 3 upper bits of the character pressed to 0.
  48. #define CTRL_KEY(k) ((k) & 0x1f)
  49. // Empty buffer
  50. #define ABUF_INIT {NULL, 0}
  51. // Version code
  52. #define TTE_VERSION "0.0.5"
  53. // Length of a tab stop
  54. #define TTE_TAB_STOP 4
  55. // Times to press Ctrl-Q before exiting
  56. #define TTE_QUIT_TIMES 2
  57. // Highlight flags
  58. #define HL_HIGHLIGHT_NUMBERS (1 << 0)
  59. #define HL_HIGHLIGHT_STRINGS (1 << 1)
  60.  
  61. /*** Data section ***/
  62.  
  63. typedef struct editor_row {
  64.     int idx; // Row own index within the file.
  65.     int size; // Size of the content (excluding NULL term)
  66.     int render_size; // Size of the rendered content
  67.     char* chars; // Row content
  68.     char* render; // Row content "rendered" for screen (for TABs).
  69.     unsigned char* highlight; // This will tell you if a character is part of a string, comment, number...
  70.     int hl_open_comment; // True if the line is part of a ML comment.
  71. } editor_row;
  72.  
  73. struct editor_syntax {
  74.     // file_type field is the name of the filetype that will be displayed
  75.     // to the user in the status bar.
  76.     char* file_type;
  77.     // file_match is an array of strings, where each string contains a
  78.     // pattern to match a filename against. If the filename matches,
  79.     // then the file will be recognized as having that filetype.
  80.     char** file_match;
  81.     // This will be a NULL-terminated array of strings, each string containing
  82.     // a keyword. To differentiate between the two types of keywords,
  83.     // we’ll terminate the second type of keywords with a pipe (|)
  84.     // character (also known as a vertical bar).
  85.     char** keywords;
  86.     // We let each language specify its own single-line comment pattern.
  87.     char* singleline_comment_start;
  88.     // flags is a bit field that will contain flags for whether to
  89.     // highlight numbers and whether to highlight strings for that
  90.     // filetype.
  91.     char* multiline_comment_start;
  92.     char* multiline_comment_end;
  93.     int flags;
  94. };
  95.  
  96. struct editor_config {
  97.     int cursor_x;
  98.     int cursor_y;
  99.     int render_x;
  100.     int row_offset; // Offset of row displayed.
  101.     int col_offset; // Offset of col displayed.
  102.     int screen_rows; // Number of rows that we can show
  103.     int screen_cols; // Number of cols that we can show
  104.     int num_rows; // Number of rows
  105.     editor_row* row;
  106.     int dirty; // To know if a file has been modified since opening.
  107.     char* file_name;
  108.     char status_msg[80];
  109.     time_t status_msg_time;
  110.     char* copied_char_buffer;
  111.     struct editor_syntax* syntax;
  112.     struct termios orig_termios;
  113. } ec;
  114.  
  115. // Having a dynamic buffer will allow us to write only one
  116. // time once the screen is refreshing, instead of doing
  117. // a lot of write's.
  118. struct a_buf {
  119.     char* buf;
  120.     int len;
  121. };
  122.  
  123. enum editor_key {
  124.     BACKSPACE = 0x7f, // 127
  125.     ARROW_LEFT = 0x3e8, // 1000, large value out of the range of a char.
  126.     ARROW_RIGHT,
  127.     ARROW_UP,
  128.     ARROW_DOWN,
  129.     PAGE_UP,
  130.     PAGE_DOWN,
  131.     HOME_KEY,
  132.     END_KEY,
  133.     DEL_KEY
  134. };
  135.  
  136. enum editor_highlight {
  137.     HL_NORMAL = 0,
  138.     HL_SL_COMMENT,
  139.     HL_ML_COMMENT,
  140.     HL_KEYWORD_1,
  141.     HL_KEYWORD_2,
  142.     HL_STRING,
  143.     HL_NUMBER,
  144.     HL_MATCH
  145. };
  146.  
  147. /*** Filetypes ***/
  148.  
  149. char* C_HL_extensions[] = {".c", ".h", ".cpp", ".hpp", ".cc", NULL}; // Array must be terminated with NULL.
  150. char* JAVA_HL_extensions[] = {".java", NULL};
  151. char* PYTHON_HL_extensions[] = {".py", NULL};
  152. char* BASH_HL_extensions[] = {".sh", NULL};
  153. char* JS_HL_extensions[] = {".js", ".jsx", NULL};
  154. char* PHP_HL_extensions[] = {".php", NULL};
  155. char* JSON_HL_extensions[] = {".json", ".jsonp", NULL};
  156. char* XML_HL_extensions[] = {".xml", NULL};
  157. char* SQL_HL_extensions[] = {".sql", NULL};
  158. char* RUBY_HL_extensions[] = {".rb", NULL};
  159.  
  160. char* C_HL_keywords[] = {
  161.     "switch", "if", "while", "for", "break", "continue", "return", "else",
  162.     "struct", "union", "typedef", "static", "enum", "class", "case", "#include",
  163.     "volatile", "register", "sizeof", "typedef", "union", "goto", "const", "auto",
  164.     "#define", "#if", "#endif", "#error", "#ifdef", "#ifndef", "#undef",
  165.  
  166.     "int|", "long|", "double|", "float|", "char|", "unsigned|", "signed|",
  167.     "void|", "bool|", NULL
  168. };
  169.  
  170. char* JAVA_HL_keywords[] = {
  171.     "switch", "if", "while", "for", "break", "continue", "return", "else",
  172.     "in", "public", "private", "protected", "static", "final", "abstract",
  173.     "enum", "class", "case", "try", "catch", "do", "extends", "implements",
  174.     "finally", "import", "instanceof", "interface", "new", "package", "super",
  175.     "native", "strictfp",
  176.     "synchronized", "this", "throw", "throws", "transient", "volatile",
  177.  
  178.     "byte|", "char|", "double|", "float|", "int|", "long|", "short|",
  179.     "boolean|", NULL
  180. };
  181.  
  182. char* PYTHON_HL_keywords[] = {
  183.     "and", "as", "assert", "break", "class", "continue", "def", "del", "elif",
  184.     "else", "except", "exec", "finally", "for", "from", "global", "if", "import",
  185.     "in", "is", "lambda", "not", "or", "pass", "print", "raise", "return", "try",
  186.     "while", "with", "yield",
  187.  
  188.     "buffer|", "bytearray|", "complex|", "False|", "float|", "frozenset|", "int|",
  189.     "list|", "long|", "None|", "set|", "str|", "tuple|", "True|", "type|",
  190.     "unicode|", "xrange|", NULL
  191. };
  192.  
  193. char* BASH_HL_keywords[] = {
  194.     "case", "do", "done", "elif", "else", "esac", "fi", "for", "function", "if",
  195.     "in", "select", "then", "time", "until", "while", "alias", "bg", "bind", "break",
  196.     "builtin", "cd", "command", "continue", "declare", "dirs", "disown", "echo",
  197.     "enable", "eval", "exec", "exit", "export", "fc", "fg", "getopts", "hash", "help",
  198.     "history", "jobs", "kill", "let", "local", "logout", "popd", "pushd", "pwd", "read",
  199.     "readonly", "return", "set", "shift", "suspend", "test", "times", "trap", "type",
  200.     "typeset", "ulimit", "umask", "unalias", "unset", "wait", "printf", NULL
  201. };
  202.  
  203. char* JS_HL_keywords[] = {
  204.     "break", "case", "catch", "class", "const", "continue", "debugger", "default",
  205.     "delete", "do", "else", "enum", "export", "extends", "finally", "for", "function",
  206.     "if", "implements", "import", "in", "instanceof", "interface", "let", "new",
  207.     "package", "private", "protected", "public", "return", "static", "super", "switch",
  208.     "this", "throw", "try", "typeof", "var", "void", "while", "with", "yield", "true",
  209.     "false", "null", "NaN", "global", "window", "prototype", "constructor", "document",
  210.     "isNaN", "arguments", "undefined",
  211.  
  212.     "Infinity|", "Array|", "Object|", "Number|", "String|", "Boolean|", "Function|",
  213.     "ArrayBuffer|", "DataView|", "Float32Array|", "Float64Array|", "Int8Array|",
  214.     "Int16Array|", "Int32Array|", "Uint8Array|", "Uint8ClampedArray|", "Uint32Array|",
  215.     "Date|", "Error|", "Map|", "RegExp|", "Symbol|", "WeakMap|", "WeakSet|", "Set|", NULL
  216. };
  217.  
  218. char* PHP_HL_keywords[] = {
  219.     "__halt_compiler", "break", "clone", "die", "empty", "endswitch", "final", "global",
  220.     "include_once", "list", "private", "return", "try", "xor", "abstract", "callable",
  221.     "const", "do", "enddeclare", "endwhile", "finally", "goto", "instanceof", "namespace",
  222.     "protected", "static", "unset", "yield", "and", "case", "continue", "echo", "endfor",
  223.     "eval", "for", "if", "insteadof", "new", "public", "switch", "use", "array", "catch",
  224.     "declare", "else", "endforeach", "exit", "foreach", "implements", "interface", "or",
  225.     "require", "throw", "var", "as", "class", "default", "elseif", "endif", "extends",
  226.     "function", "include", "isset", "print", "require_once", "trait", "while", NULL
  227. };
  228.  
  229. char* JSON_HL_keywords[] = {
  230.     NULL
  231. };
  232.  
  233. char* XML_HL_keywords[] = {
  234.     NULL
  235. };
  236.  
  237. char* SQL_HL_keywords[] = {
  238.     "SELECT", "FROM", "DROP", "CREATE", "TABLE", "DEFAULT", "FOREIGN", "UPDATE", "LOCK",
  239.     "INSERT", "INTO", "VALUES", "LOCK", "UNLOCK", "WHERE", "DINSTINCT", "BETWEEN", "NOT",
  240.     "NULL", "TO", "ON", "ORDER", "GROUP", "IF", "BY", "HAVING", "USING", "UNION", "UNIQUE",
  241.     "AUTO_INCREMENT", "LIKE", "WITH", "INNER", "OUTER", "JOIN", "COLUMN", "DATABASE", "EXISTS",
  242.     "NATURAL", "LIMIT", "UNSIGNED", "MAX", "MIN", "PRECISION", "ALTER", "DELETE", "CASCADE",
  243.     "PRIMARY", "KEY", "CONSTRAINT", "ENGINE", "CHARSET", "REFERENCES", "WRITE",
  244.  
  245.     "BIT|", "TINYINT|", "BOOL|", "BOOLEAN|", "SMALLINT|", "MEDIUMINT|", "INT|", "INTEGER|",
  246.     "BIGINT|", "DOUBLE|", "DECIMAL|", "DEC|" "FLOAT|", "DATE|", "DATETIME|", "TIMESTAMP|",
  247.     "TIME|", "YEAR|", "CHAR|", "VARCHAR|", "TEXT|", "ENUM|", "SET|", "BLOB|", "VARBINARY|",
  248.     "TINYBLOB|", "TINYTEXT|", "MEDIUMBLOB|", "MEDIUMTEXT|", "LONGTEXT|",
  249.  
  250.     "select", "from", "drop", "create", "table", "default", "foreign", "update", "lock",
  251.     "insert", "into", "values", "lock", "unlock", "where", "dinstinct", "between", "not",
  252.     "null", "to", "on", "order", "group", "if", "by", "having", "using", "union", "unique",
  253.     "auto_increment", "like", "with", "inner", "outer", "join", "column", "database", "exists",
  254.     "natural", "limit", "unsigned", "max", "min", "precision", "alter", "delete", "cascade",
  255.     "primary", "key", "constraint", "engine", "charset", "references", "write",
  256.  
  257.     "bit|", "tinyint|", "bool|", "boolean|", "smallint|", "mediumint|", "int|", "integer|",
  258.     "bigint|", "double|", "decimal|", "dec|" "float|", "date|", "datetime|", "timestamp|",
  259.     "time|", "year|", "char|", "varchar|", "text|", "enum|", "set|", "blob|", "varbinary|",
  260.     "tinyblob|", "tinytext|", "mediumblob|", "mediumtext|", "longtext|", NULL
  261. };
  262.  
  263. char* RUBY_HL_keywords[] = {
  264.     "__ENCODING__", "__LINE__", "__FILE__", "BEGIN", "END", "alias", "and", "begin", "break",
  265.     "case", "class", "def", "defined?", "do", "else", "elsif", "end", "ensure", "for", "if",
  266.     "in", "module", "next", "not", "or", "redo", "rescue", "retry", "return", "self", "super",
  267.     "then", "undef", "unless", "until", "when", "while", "yield", NULL
  268. };
  269.  
  270. struct editor_syntax HL_DB[] = {
  271.     {
  272.         "c",
  273.         C_HL_extensions,
  274.         C_HL_keywords,
  275.         "//",
  276.         "/*",
  277.         "*/",
  278.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  279.     },
  280.     {
  281.         "java",
  282.         JAVA_HL_extensions,
  283.         JAVA_HL_keywords,
  284.         "//",
  285.         "/*",
  286.         "*/",
  287.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  288.     },
  289.     {
  290.         "python",
  291.         PYTHON_HL_extensions,
  292.         PYTHON_HL_keywords,
  293.         "#",
  294.         "'''",
  295.         "'''",
  296.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  297.     },
  298.     {
  299.         "bash",
  300.         BASH_HL_extensions,
  301.         BASH_HL_keywords,
  302.         "#",
  303.         NULL,
  304.         NULL,
  305.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  306.     },
  307.     {
  308.         "js",
  309.         JS_HL_extensions,
  310.         JS_HL_keywords,
  311.         "//",
  312.         "/*",
  313.         "*/",
  314.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  315.     },
  316.     {
  317.         "php",
  318.         PHP_HL_extensions,
  319.         PHP_HL_keywords,
  320.         "//",
  321.         "/*",
  322.         "*/",
  323.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  324.     },
  325.     {
  326.         "json",
  327.         JSON_HL_extensions,
  328.         JSON_HL_keywords,
  329.         NULL,
  330.         NULL,
  331.         NULL,
  332.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  333.     },
  334.     {
  335.         "xml",
  336.         XML_HL_extensions,
  337.         XML_HL_keywords,
  338.         NULL,
  339.         NULL,
  340.         NULL,
  341.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  342.     },
  343.     {
  344.         "sql",
  345.         SQL_HL_extensions,
  346.         SQL_HL_keywords,
  347.         "--",
  348.         "/*",
  349.         "*/",
  350.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  351.     },
  352.     {
  353.         "ruby",
  354.         RUBY_HL_extensions,
  355.         RUBY_HL_keywords,
  356.         "#",
  357.         "=begin",
  358.         "=end",
  359.         HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
  360.     }
  361. };
  362.  
  363. // Size of the "Hightlight Database" (HL_DB).
  364. #define HL_DB_ENTRIES (sizeof(HL_DB) / sizeof(HL_DB[0]))
  365.  
  366. /*** Declarations section ***/
  367.  
  368. void editorClearScreen();
  369.  
  370. void editorRefreshScreen();
  371.  
  372. void editorSetStatusMessage(const char* msg, ...);
  373.  
  374. void consoleBufferOpen();
  375.  
  376. void abufFree();
  377.  
  378. void abufAppend();
  379.  
  380. char *editorPrompt(char* prompt, void (*callback)(char*, int));
  381.  
  382. void editorRowAppendString(editor_row* row, char* s, size_t len);
  383.  
  384. void editorInsertNewline();
  385.  
  386. /*** Terminal section ***/
  387.  
  388. void die(const char* s) {
  389.     editorClearScreen();
  390.     // perror looks for global errno variable and then prints
  391.     // a descriptive error mesage for it.
  392.     perror(s);
  393.     printf("\r\n");
  394.     exit(1);
  395. }
  396.  
  397. void disableRawMode() {
  398.     if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &ec.orig_termios) == -1)
  399.         die("Failed to disable raw mode");
  400. }
  401.  
  402. void enableRawMode() {
  403.     // Save original terminal state into orig_termios.
  404.     if (tcgetattr(STDIN_FILENO, &ec.orig_termios) == -1)
  405.         die("Failed to get current terminal state");
  406.     // At exit, restore the original state.
  407.     atexit(disableRawMode);
  408.  
  409.     // Modify the original state to enter in raw mode.
  410.     struct termios raw = ec.orig_termios;
  411.     // This disables Ctrl-M, Ctrl-S and Ctrl-Q commands.
  412.     // (BRKINT, INPCK and ISTRIP are not estrictly mandatory,
  413.     // but it is recommended to turn them off in case any
  414.     // system needs it).
  415.     raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
  416.     // Turning off all output processing (\r\n).
  417.     raw.c_oflag &= ~(OPOST);
  418.     // Setting character size to 8 bits per byte (it should be
  419.     // like that on most systems, but whatever).
  420.     raw.c_cflag |= (CS8);
  421.     // Using NOT operator on ECHO | ICANON | IEXTEN | ISIG and
  422.     // then bitwise-AND them with flags field in order to
  423.     // force c_lflag 4th bit to become 0. This disables
  424.     // chars being printed (ECHO) and let us turn off
  425.     // canonical mode in order to read input byte-by-byte
  426.     // instead of line-by-line (ICANON), ISIG disables
  427.     // Ctrl-C command and IEXTEN the Ctrl-V one.
  428.     raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
  429.     // read() function now returns as soon as there is any
  430.     // input to be read.
  431.     raw.c_cc[VMIN] = 0;
  432.     // Forcing read() function to return every 1/10 of a
  433.     // second if there is nothing to read.
  434.     raw.c_cc[VTIME] = 1;
  435.  
  436.     consoleBufferOpen();
  437.  
  438.     if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1)
  439.         die("Failed to set raw mode");
  440. }
  441.  
  442. int editorReadKey() {
  443.     int nread;
  444.     char c;
  445.     while ((nread = read(STDIN_FILENO, &c, 1)) != 1) {
  446.         // Ignoring EAGAIN to make it work on Cygwin.
  447.         if (nread == -1 && errno != EAGAIN)
  448.             die("Error reading input");
  449.     }
  450.  
  451.     // Check escape sequences, if first byte
  452.     // is an escape character then...
  453.     if (c == '\x1b') {
  454.         char seq[3];
  455.  
  456.         if (read(STDIN_FILENO, &seq[0], 1) != 1 ||
  457.             read(STDIN_FILENO, &seq[1], 1) != 1)
  458.             return '\x1b';
  459.  
  460.         if (seq[0] == '[') {
  461.             if (seq[1] >= '0' && seq[1] <= '9') {
  462.                 if (read(STDIN_FILENO, &seq[2], 1) != 1)
  463.                     return '\x1b';
  464.                 if (seq[2] == '~') {
  465.                     switch (seq[1]) {
  466.                         // Home and End keys may be sent in many ways depending on the OS
  467.                         // \x1b[1~, \x1b[7~, \x1b[4~, \x1b[8~
  468.                         case '1':
  469.                         case '7':
  470.                             return HOME_KEY;
  471.                         case '4':
  472.                         case '8':
  473.                             return END_KEY;
  474.                         // Del key is sent as \x1b[3~
  475.                         case '3':
  476.                             return DEL_KEY;
  477.                         // Page Up and Page Down send '\x1b', '[', '5' or '6' and '~'.
  478.                         case '5': return PAGE_UP;
  479.                         case '6': return PAGE_DOWN;
  480.                     }
  481.                 }
  482.             } else {
  483.                 switch (seq[1]) {
  484.                     // Arrow keys send multiple bytes starting with '\x1b', '[''
  485.                     // and followed by an 'A', 'B', 'C' or 'D' depending on which
  486.                     // arrow is pressed.
  487.                     case 'A': return ARROW_UP;
  488.                     case 'B': return ARROW_DOWN;
  489.                     case 'C': return ARROW_RIGHT;
  490.                     case 'D': return ARROW_LEFT;
  491.                     // Home key can also be sent as \x1b[H
  492.                     case 'H': return HOME_KEY;
  493.                     // End key can also be sent as \x1b[F
  494.                     case 'F': return END_KEY;
  495.                 }
  496.             }
  497.         } else if (seq[0] == 'O') {
  498.             switch (seq[1]) {
  499.                 // Yes, Home key can ALSO be sent as \x1bOH
  500.                 case 'H': return HOME_KEY;
  501.                 // And... End key as \x1bOF
  502.                 case 'F': return END_KEY;
  503.             }
  504.         }
  505.         return '\x1b';
  506.     } else {
  507.         return c;
  508.     }
  509. }
  510.  
  511. int getWindowSize(int* screen_rows, int* screen_cols) {
  512.     struct winsize ws;
  513.  
  514.     // Getting window size thanks to ioctl into the given
  515.     // winsize struct.
  516.     if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
  517.         return -1;
  518.     } else {
  519.         *screen_cols = ws.ws_col;
  520.         *screen_rows = ws.ws_row;
  521.         return 0;
  522.     }
  523. }
  524.  
  525. void editorUpdateWindowSize() {
  526.     if (getWindowSize(&ec.screen_rows, &ec.screen_cols) == -1)
  527.         die("Failed to get window size");
  528.     ec.screen_rows -= 2; // Room for the status bar.
  529. }
  530.  
  531. void editorHandleSigwinch() {
  532.     editorUpdateWindowSize();
  533.     if (ec.cursor_y > ec.screen_rows)
  534.         ec.cursor_y = ec.screen_rows - 1;
  535.     if (ec.cursor_x > ec.screen_cols)
  536.         ec.cursor_x = ec.screen_cols - 1;
  537.     editorRefreshScreen();
  538. }
  539.  
  540. void editorHandleSigcont() {
  541.     disableRawMode();
  542.     consoleBufferOpen();
  543.     enableRawMode();
  544.     editorRefreshScreen();
  545. }
  546.  
  547. void consoleBufferOpen() {
  548.     // Switch to another terminal buffer in order to be able to restore state at exit
  549.     // by calling consoleBufferClose().
  550.     if (write(STDOUT_FILENO, "\x1b[?47h", 6) == -1)
  551.         die("Error changing terminal buffer");
  552. }
  553.  
  554. void consoleBufferClose() {
  555.     // Restore console to the state tte opened.
  556.     if (write(STDOUT_FILENO, "\x1b[?9l", 5) == -1 ||
  557.         write(STDOUT_FILENO, "\x1b[?47l", 6) == -1)
  558.         die("Error restoring buffer state");
  559.  
  560.     /*struct a_buf ab = {.buf = NULL, .len = 0};
  561.     char* buf = NULL;
  562.     if (asprintf(&buf, "\x1b[%d;%dH\r\n", ec.screen_rows + 1, 1) == -1)
  563.         die("Error restoring buffer state");
  564.     abufAppend(&ab, buf, strlen(buf));
  565.     free(buf);
  566.  
  567.     if (write(STDOUT_FILENO, ab.buf, ab.len) == -1)
  568.         die("Error restoring buffer state");
  569.     abufFree(&ab);*/
  570.  
  571.     editorClearScreen();
  572. }
  573.  
  574. /*** Syntax highlighting ***/
  575.  
  576. int isSeparator(int c) {
  577.     // strchr() looks to see if any one of the characters in the first string
  578.     // appear in the second string. If so, it returns a pointer to the
  579.     // character in the second string that matched. Otherwise, it
  580.     // returns NULL.
  581.     return isspace(c) || c == '\0' || strchr(",.()+-/*=~%<>[]:;", c) != NULL;
  582. }
  583.  
  584. int isAlsoNumber(int c) {
  585.     return c == '.' || c == 'x' || c == 'a' || c == 'b' || c == 'c' || c == 'd' || c == 'e' || c == 'f';
  586. }
  587.  
  588. void editorUpdateSyntax(editor_row* row) {
  589.     row -> highlight = realloc(row -> highlight, row -> render_size);
  590.     // void * memset ( void * ptr, int value, size_t num );
  591.     // Sets the first num bytes of the block of memory pointed by ptr to
  592.     // the specified value. With this we set all characters to HL_NORMAL.
  593.     memset(row -> highlight, HL_NORMAL, row -> render_size);
  594.  
  595.     if (ec.syntax == NULL)
  596.         return;
  597.  
  598.     char** keywords = ec.syntax -> keywords;
  599.  
  600.     char* scs = ec.syntax -> singleline_comment_start;
  601.     char* mcs = ec.syntax -> multiline_comment_start;
  602.     char* mce = ec.syntax -> multiline_comment_end;
  603.  
  604.     int scs_len = scs ? strlen(scs) : 0;
  605.     int mcs_len = mcs ? strlen(mcs) : 0;
  606.     int mce_len = mce ? strlen(mce) : 0;
  607.  
  608.     int prev_sep = 1; // True (1) if the previous char is a separator, false otherwise.
  609.     int in_string = 0; // If != 0, inside a string. We also keep track if it's ' or "
  610.     int in_comment = (row -> idx > 0 && ec.row[row -> idx - 1].hl_open_comment); // This is ONLY used on ML comments.
  611.  
  612.     int i = 0;
  613.     while (i < row -> render_size) {
  614.         char c = row -> render[i];
  615.         // Highlight type of the previous character.
  616.         unsigned char prev_highlight = (i > 0) ? row -> highlight[i - 1] : HL_NORMAL;
  617.  
  618.         if (scs_len && !in_string && !in_comment) {
  619.             // int strncmp ( const char * str1, const char * str2, size_t num );
  620.             // Compares up to num characters of the C string str1 to those of the C string str2.
  621.             // This function starts comparing the first character of each string. If they are
  622.             // equal to each other, it continues with the following pairs until the characters
  623.             // differ, until a terminating null-character is reached, or until num characters
  624.             // match in both strings, whichever happens first.
  625.             if (!strncmp(&row -> render[i], scs, scs_len)) {
  626.                 memset(&row -> highlight[i], HL_SL_COMMENT, row -> render_size - i);
  627.                 break;
  628.             }
  629.         }
  630.  
  631.         if (mcs_len && mce_len && !in_string) {
  632.             if (in_comment) {
  633.                 row -> highlight[i] = HL_ML_COMMENT;
  634.                 if (!strncmp(&row -> render[i], mce, mce_len)) {
  635.                     memset(&row -> highlight[i], HL_ML_COMMENT, mce_len);
  636.                     i += mce_len;
  637.                     in_comment = 0;
  638.                     prev_sep = 1;
  639.                     continue;
  640.                 } else {
  641.                     i++;
  642.                     continue;
  643.                 }
  644.             } else if (!strncmp(&row -> render[i], mcs, mcs_len)) {
  645.                 memset(&row -> highlight[i], HL_ML_COMMENT, mcs_len);
  646.                 i += mcs_len;
  647.                 in_comment = 1;
  648.                 continue;
  649.             }
  650.  
  651.         }
  652.  
  653.         if (ec.syntax -> flags & HL_HIGHLIGHT_STRINGS) {
  654.             if (in_string) {
  655.                 row -> highlight[i] = HL_STRING;
  656.                 // If we’re in a string and the current character is a backslash (\),
  657.                 // and there’s at least one more character in that line that comes
  658.                 // after the backslash, then we highlight the character that comes
  659.                 // after the backslash with HL_STRING and consume it. We increment
  660.                 // i by 2 to consume both characters at once.
  661.                 if (c == '\\' && i + 1 < row -> render_size) {
  662.                     row -> highlight[i + 1] = HL_STRING;
  663.                     i += 2;
  664.                     continue;
  665.                 }
  666.  
  667.                 if (c == in_string)
  668.                     in_string = 0;
  669.                 i++;
  670.                 prev_sep = 1;
  671.                 continue;
  672.             } else {
  673.                 if (c == '"' || c == '\'') {
  674.                     in_string = c;
  675.                     row -> highlight[i] = HL_STRING;
  676.                     i++;
  677.                     continue;
  678.                 }
  679.             }
  680.         }
  681.  
  682.         if (ec.syntax -> flags & HL_HIGHLIGHT_NUMBERS) {
  683.             if ((isdigit(c) && (prev_sep || prev_highlight == HL_NUMBER)) ||
  684.                 (isAlsoNumber(c) && prev_highlight == HL_NUMBER)) {
  685.                 row -> highlight[i] = HL_NUMBER;
  686.                 i++;
  687.                 prev_sep = 0;
  688.                 continue;
  689.             }
  690.         }
  691.  
  692.         if (prev_sep) {
  693.             int j;
  694.             for (j = 0; keywords[j]; j++) {
  695.                 int kw_len = strlen(keywords[j]);
  696.                 int kw_2 = keywords[j][kw_len - 1] == '|';
  697.                 if (kw_2)
  698.                     kw_len--;
  699.  
  700.                 // Keywords require a separator both before and after the keyword.
  701.                 if (!strncmp(&row -> render[i], keywords[j], kw_len) &&
  702.                     isSeparator(row -> render[i + kw_len])) {
  703.                     memset(&row -> highlight[i], kw_2 ? HL_KEYWORD_2 : HL_KEYWORD_1, kw_len);
  704.                     i += kw_len;
  705.                     break;
  706.                 }
  707.             }
  708.             if (keywords[j] != NULL) {
  709.                 prev_sep = 0;
  710.                 continue;
  711.             }
  712.         }
  713.  
  714.         prev_sep = isSeparator(c);
  715.         i++;
  716.     }
  717.  
  718.     int changed = (row -> hl_open_comment != in_comment);
  719.     // This tells us whether the row ended as an unclosed multi-line
  720.     // comment or not.
  721.     row -> hl_open_comment = in_comment;
  722.     // A user could comment out an entire file just by changing one line.
  723.     // So it seems like we need to update the syntax of all the lines
  724.     // following the current line. However, we know the highlighting
  725.     // of the next line will not change if the value of this line’s
  726.     // // // hl_open_comment did not change. So we check if it changed, and
  727.     // // only call editorUpdateSyntax() on the next line if
  728.     // hl_open_comment changed (and if there is a next line in the file).
  729.     // Because editorUpdateSyntax() keeps calling itself with the next
  730.     // line, the change will continue to propagate to more and more lines
  731.     // until one of them is unchanged, at which point we know that all
  732.     // the lines after that one must be unchanged as well.
  733.     if (changed && row -> idx + 1 < ec.num_rows)
  734.         editorUpdateSyntax(&ec.row[row -> idx + 1]);
  735. }
  736.  
  737. int editorSyntaxToColor(int highlight) {
  738.     // We return ANSI codes for colors.
  739.     // See https://en.wikipedia.org/wiki/ANSI_escape_code#Colors
  740.     // for a list of them.
  741.     switch (highlight) {
  742.         case HL_SL_COMMENT:
  743.         case HL_ML_COMMENT: return 36;
  744.         case HL_KEYWORD_1: return 31;
  745.         case HL_KEYWORD_2: return 32;
  746.         case HL_STRING: return 33;
  747.         case HL_NUMBER: return 35;
  748.         case HL_MATCH: return 34;
  749.         default: return 37;
  750.     }
  751. }
  752.  
  753. void editorSelectSyntaxHighlight() {
  754.     ec.syntax = NULL;
  755.     if (ec.file_name == NULL)
  756.         return;
  757.  
  758.     for (unsigned int j = 0; j < HL_DB_ENTRIES; j++) {
  759.         struct editor_syntax* es = &HL_DB[j];
  760.         unsigned int i = 0;
  761.  
  762.         while (es -> file_match[i]) {
  763.             char* p = strstr(ec.file_name, es -> file_match[i]);
  764.             if (p != NULL) {
  765.                 // Returns a pointer to the first occurrence of str2 in str1,
  766.                 // or a null pointer if str2 is not part of str1.
  767.                 int pat_len = strlen(es -> file_match[i]);
  768.                 if (es -> file_match[i][0] != '.' || p[pat_len] == '\0') {
  769.                     ec.syntax = es;
  770.  
  771.                     int file_row;
  772.                     for (file_row = 0; file_row < ec.num_rows; file_row++) {
  773.                         editorUpdateSyntax(&ec.row[file_row]);
  774.                     }
  775.  
  776.                     return;
  777.                 }
  778.             }
  779.             i++;
  780.         }
  781.     }
  782. }
  783.  
  784. /*** Row operations ***/
  785.  
  786. int editorRowCursorXToRenderX(editor_row* row, int cursor_x) {
  787.     int render_x = 0;
  788.     int j;
  789.     // For each character, if its a tab we use rx % TTE_TAB_STOP
  790.     // to find out how many columns we are to the right of the last
  791.     // tab stop, and then subtract that from TTE_TAB_STOP - 1 to
  792.     // find out how many columns we are to the left of the next tab
  793.     // stop. We add that amount to rx to get just to the left of the
  794.     // next tab stop, and then the unconditional rx++ statement gets
  795.     // us right on the next tab stop. Notice how this works even if
  796.     // we are currently on a tab stop.
  797.     for (j = 0; j < cursor_x; j++) {
  798.         if (row -> chars[j] == '\t')
  799.             render_x += (TTE_TAB_STOP - 1) - (render_x % TTE_TAB_STOP);
  800.         render_x++;
  801.     }
  802.     return render_x;
  803. }
  804.  
  805. int editorRowRenderXToCursorX(editor_row* row, int render_x) {
  806.     int cur_render_x = 0;
  807.     int cursor_x;
  808.     for (cursor_x = 0; cursor_x < row -> size; cursor_x++) {
  809.         if (row -> chars[cursor_x] == '\t')
  810.             cur_render_x += (TTE_TAB_STOP - 1) - (cur_render_x % TTE_TAB_STOP);
  811.         cur_render_x++;
  812.  
  813.         if (cur_render_x > render_x)
  814.             return cursor_x;
  815.     }
  816.     return cursor_x;
  817. }
  818.  
  819. void editorUpdateRow(editor_row* row) {
  820.     // First, we have to loop through the chars of the row
  821.     // and count the tabs in order to know how much memory
  822.     // to allocate for render. The maximum number of characters
  823.     // needed for each tab is 8. row->size already counts 1 for
  824.     // each tab, so we multiply the number of tabs by 7 and add
  825.     // that to row->size to get the maximum amount of memory we'll
  826.     // need for the rendered row.
  827.     int tabs = 0;
  828.     int j;
  829.     for (j = 0; j < row -> size; j++) {
  830.         if (row -> chars[j] == '\t')
  831.             tabs++;
  832.     }
  833.     free(row -> render);
  834.     row -> render = malloc(row -> size + tabs * (TTE_TAB_STOP - 1) + 1);
  835.  
  836.     // After allocating the memory, we check whether the current character
  837.     // is a tab. If it is, we append one space (because each tab must
  838.     // advance the cursor forward at least one column), and then append
  839.     // spaces until we get to a tab stop, which is a column that is
  840.     // divisible by 8
  841.     int idx = 0;
  842.     for (j = 0; j < row -> size; j++) {
  843.         if (row -> chars[j] == '\t') {
  844.             row -> render[idx++] = ' ';
  845.             while (idx % TTE_TAB_STOP != 0)
  846.                 row -> render[idx++] = ' ';
  847.         } else
  848.             row -> render[idx++] = row -> chars[j];
  849.     }
  850.     row -> render[idx] = '\0';
  851.     row -> render_size = idx;
  852.  
  853.     editorUpdateSyntax(row);
  854. }
  855.  
  856. void editorInsertRow(int at, char* s, size_t line_len) {
  857.     if (at < 0 || at > ec.num_rows)
  858.         return;
  859.  
  860.     ec.row = realloc(ec.row, sizeof(editor_row) * (ec.num_rows + 1));
  861.     memmove(&ec.row[at + 1], &ec.row[at], sizeof(editor_row) * (ec.num_rows - at));
  862.  
  863.     for (int j = at + 1; j <= ec.num_rows; j++) {
  864.         ec.row[j].idx++;
  865.     }
  866.  
  867.     ec.row[at].idx = at;
  868.  
  869.     ec.row[at].size = line_len;
  870.     ec.row[at].chars = malloc(line_len + 1); // We want to add terminator char '\0' at the end
  871.     memcpy(ec.row[at].chars, s, line_len);
  872.     ec.row[at].chars[line_len] = '\0';
  873.  
  874.     ec.row[at].render_size = 0;
  875.     ec.row[at].render = NULL;
  876.     ec.row[at].highlight = NULL;
  877.     ec.row[at].hl_open_comment = 0;
  878.     editorUpdateRow(&ec.row[at]);
  879.  
  880.     ec.num_rows++;
  881.     ec.dirty++;
  882. }
  883.  
  884. void editorFreeRow(editor_row* row) {
  885.     free(row -> render);
  886.     free(row -> chars);
  887.     free(row -> highlight);
  888. }
  889.  
  890. void editorDelRow(int at) {
  891.     if (at < 0 || at >= ec.num_rows)
  892.         return;
  893.     editorFreeRow(&ec.row[at]);
  894.     memmove(&ec.row[at], &ec.row[at + 1], sizeof(editor_row) * (ec.num_rows - at - 1));
  895.  
  896.     for (int j = at; j < ec.num_rows - 1; j++) {
  897.         ec.row[j].idx--;
  898.     }
  899.  
  900.     ec.num_rows--;
  901.     ec.dirty++;
  902. }
  903.  
  904. // -1 down, 1 up
  905. void editorFlipRow(int dir) {
  906.     editor_row c_row = ec.row[ec.cursor_y];
  907.     ec.row[ec.cursor_y] = ec.row[ec.cursor_y - dir];
  908.     ec.row[ec.cursor_y - dir] = c_row;
  909.  
  910.     ec.row[ec.cursor_y].idx += dir;
  911.     ec.row[ec.cursor_y - dir].idx -= dir;
  912.  
  913.     int first = (dir == 1) ? ec.cursor_y - 1 : ec.cursor_y;
  914.     editorUpdateSyntax(&ec.row[first]);
  915.     editorUpdateSyntax(&ec.row[first] + 1);
  916.     if (ec.num_rows - ec.cursor_y > 2)
  917.       editorUpdateSyntax(&ec.row[first] + 2);
  918.  
  919.     ec.cursor_y -= dir;
  920.     ec.dirty++;
  921. }
  922.  
  923. void editorCopy(int cut) {
  924.     ec.copied_char_buffer = realloc(ec.copied_char_buffer, strlen(ec.row[ec.cursor_y].chars) + 1);
  925.     strcpy(ec.copied_char_buffer, ec.row[ec.cursor_y].chars);
  926.     editorSetStatusMessage(cut ? "Content cut" : "Content copied");
  927. }
  928.  
  929. void editorCut() {
  930.     editorCopy(-1);
  931.     editorDelRow(ec.cursor_y);
  932.     if (ec.num_rows - ec.cursor_y > 0)
  933.       editorUpdateSyntax(&ec.row[ec.cursor_y]);
  934.     if (ec.num_rows - ec.cursor_y > 1)
  935.       editorUpdateSyntax(&ec.row[ec.cursor_y + 1]);
  936.     ec.cursor_x = ec.cursor_y == ec.num_rows ? 0 : ec.row[ec.cursor_y].size;
  937. }
  938.  
  939. void editorPaste() {
  940.     if (ec.copied_char_buffer == NULL)
  941.       return;
  942.  
  943.     if (ec.cursor_y == ec.num_rows)
  944.       editorInsertRow(ec.cursor_y, ec.copied_char_buffer, strlen(ec.copied_char_buffer));
  945.     else
  946.       editorRowAppendString(&ec.row[ec.cursor_y], ec.copied_char_buffer, strlen(ec.copied_char_buffer));
  947.     ec.cursor_x += strlen(ec.copied_char_buffer);
  948. }
  949.  
  950. void editorRowInsertChar(editor_row* row, int at, int c) {
  951.     if (at < 0 || at > row -> size)
  952.         at = row -> size;
  953.     // We need to allocate 2 bytes because we also have to make room for
  954.     // the null byte.
  955.     row -> chars = realloc(row -> chars, row -> size + 2);
  956.     // memmove it's like memcpy(), but is safe to use when the source and
  957.     // destination arrays overlap
  958.     memmove(&row -> chars[at + 1], &row -> chars[at], row -> size - at + 1);
  959.     row -> size++;
  960.     row -> chars[at] = c;
  961.     editorUpdateRow(row);
  962.     ec.dirty++; // This way we can see "how dirty" a file is.
  963. }
  964.  
  965. void editorInsertNewline() {
  966.     // If we're at the beginning of a line, all we have to do is insert
  967.     // a new blank row before the line we're on.
  968.     if (ec.cursor_x == 0) {
  969.         editorInsertRow(ec.cursor_y, "", 0);
  970.     // Otherwise, we have to split the line we're on into two rows.
  971.     } else {
  972.         editor_row* row = &ec.row[ec.cursor_y];
  973.         editorInsertRow(ec.cursor_y + 1, &row -> chars[ec.cursor_x], row -> size - ec.cursor_x);
  974.         row = &ec.row[ec.cursor_y];
  975.         row -> size = ec.cursor_x;
  976.         row -> chars[row -> size] = '\0';
  977.         editorUpdateRow(row);
  978.     }
  979.     ec.cursor_y++;
  980.     ec.cursor_x = 0;
  981. }
  982.  
  983. void editorRowAppendString(editor_row* row, char* s, size_t len) {
  984.     row -> chars = realloc(row -> chars, row -> size + len + 1);
  985.     memcpy(&row -> chars[row -> size], s, len);
  986.     row -> size += len;
  987.     row -> chars[row -> size] = '\0';
  988.     editorUpdateRow(row);
  989.     ec.dirty++;
  990. }
  991.  
  992. void editorRowDelChar(editor_row* row, int at) {
  993.     if (at < 0 || at >= row -> size)
  994.         return;
  995.     // Overwriting the deleted character with the characters that come
  996.     // after it.
  997.     memmove(&row -> chars[at], &row -> chars[at + 1], row -> size - at);
  998.     row -> size--;
  999.     editorUpdateRow(row);
  1000.     ec.dirty++;
  1001. }
  1002.  
  1003. /*** Editor operations ***/
  1004.  
  1005. void editorInsertChar(int c) {
  1006.     // If this is true, the cursor is on the tilde line after the end of
  1007.     // the file, so we need to append a new row to the file before inserting
  1008.     // a character there.
  1009.     if (ec.cursor_y == ec.num_rows)
  1010.         editorInsertRow(ec.num_rows, "", 0);
  1011.     editorRowInsertChar(&ec.row[ec.cursor_y], ec.cursor_x, c);
  1012.     ec.cursor_x++; // This way we can see "how dirty" a file is.
  1013. }
  1014.  
  1015. void editorDelChar() {
  1016.     // If the cursor is past the end of the file, there's nothing to delete.
  1017.     if (ec.cursor_y == ec.num_rows)
  1018.         return;
  1019.     // Cursor is at the beginning of a file, there's nothing to delete.
  1020.     if (ec.cursor_x == 0 && ec.cursor_y == 0)
  1021.         return;
  1022.  
  1023.     editor_row* row = &ec.row[ec.cursor_y];
  1024.     if (ec.cursor_x > 0) {
  1025.         editorRowDelChar(row, ec.cursor_x - 1);
  1026.         ec.cursor_x--;
  1027.     // Deleting a line and moving up all the content.
  1028.     } else {
  1029.         ec.cursor_x = ec.row[ec.cursor_y - 1].size;
  1030.         editorRowAppendString(&ec.row[ec.cursor_y -1], row -> chars, row -> size);
  1031.         editorDelRow(ec.cursor_y);
  1032.         ec.cursor_y--;
  1033.     }
  1034. }
  1035.  
  1036. /*** File I/O ***/
  1037.  
  1038. char* editorRowsToString(int* buf_len) {
  1039.     int total_len = 0;
  1040.     int j;
  1041.     // Adding up the lengths of each row of text, adding 1
  1042.     // to each one for the newline character we'll add to
  1043.     // the end of each line.
  1044.     for (j = 0; j < ec.num_rows; j++) {
  1045.         total_len += ec.row[j].size + 1;
  1046.     }
  1047.     *buf_len = total_len;
  1048.  
  1049.     char* buf = malloc(total_len);
  1050.     char* p = buf;
  1051.     // Copying the contents of each row to the end of the
  1052.     // buffer, appending a newline character after each
  1053.     // row.
  1054.     for (j = 0; j < ec.num_rows; j++) {
  1055.         memcpy(p, ec.row[j].chars, ec.row[j].size);
  1056.         p += ec.row[j].size;
  1057.         *p = '\n';
  1058.         p++;
  1059.     }
  1060.  
  1061.     return buf;
  1062. }
  1063.  
  1064. void editorOpen(char* file_name) {
  1065.     free(ec.file_name);
  1066.     ec.file_name = strdup(file_name);
  1067.  
  1068.     editorSelectSyntaxHighlight();
  1069.  
  1070.     FILE* file = fopen(file_name, "r+");
  1071.     if (!file)
  1072.         die("Failed to open the file");
  1073.  
  1074.     char* line = NULL;
  1075.     // Unsigned int of at least 16 bit.
  1076.     size_t line_cap = 0;
  1077.     // Bigger than int
  1078.     ssize_t line_len;
  1079.     while ((line_len = getline(&line, &line_cap, file)) != -1) {
  1080.         // We already know each row represents one line of text, there's no need
  1081.         // to keep carriage return and newline characters.
  1082.         if (line_len > 0 && (line[line_len - 1] == '\n' || line[line_len - 1] == '\r'))
  1083.             line_len--;
  1084.         editorInsertRow(ec.num_rows, line, line_len);
  1085.     }
  1086.     free(line);
  1087.     fclose(file);
  1088.     ec.dirty = 0;
  1089. }
  1090.  
  1091. void editorSave() {
  1092.     if (ec.file_name == NULL) {
  1093.         ec.file_name = editorPrompt("Save as: %s (ESC to cancel)", NULL);
  1094.         if (ec.file_name == NULL) {
  1095.             editorSetStatusMessage("Save aborted");
  1096.             return;
  1097.         }
  1098.         editorSelectSyntaxHighlight();
  1099.     }
  1100.  
  1101.     int len;
  1102.     char* buf = editorRowsToString(&len);
  1103.  
  1104.     // We want to create if it doesn't already exist (O_CREAT flag), giving
  1105.     // 0644 permissions (the standard ones). O_RDWR stands for reading and
  1106.     // writing.
  1107.     int fd = open(ec.file_name, O_RDWR | O_CREAT, 0644);
  1108.     if (fd != -1) {
  1109.         // ftruncate sets the file's size to the specified length.
  1110.         if (ftruncate(fd, len) != -1) {
  1111.             // Writing the file.
  1112.             if (write(fd, buf, len) == len) {
  1113.                 close(fd);
  1114.                 free(buf);
  1115.                 ec.dirty = 0;
  1116.                 editorSetStatusMessage("%d bytes written to disk", len);
  1117.                 return;
  1118.             }
  1119.         }
  1120.         close(fd);
  1121.     }
  1122.  
  1123.     free(buf);
  1124.     editorSetStatusMessage("Cant's save file. Error occurred: %s", strerror(errno));
  1125. }
  1126.  
  1127. /*** Search section ***/
  1128.  
  1129. void editorSearchCallback(char* query, int key) {
  1130.     // Index of the row that the last match was on, -1 if there was
  1131.     // no last match.
  1132.     static int last_match = -1;
  1133.     // 1 for searching forward and -1 for searching backwards.
  1134.     static int direction = 1;
  1135.  
  1136.     static int saved_highlight_line;
  1137.     static char* saved_hightlight = NULL;
  1138.  
  1139.     if (saved_hightlight) {
  1140.         memcpy(ec.row[saved_highlight_line].highlight, saved_hightlight, ec.row[saved_highlight_line].render_size);
  1141.         free(saved_hightlight);
  1142.         saved_hightlight = NULL;
  1143.     }
  1144.  
  1145.     // Checking if the user pressed Enter or Escape, in which case
  1146.     // they are leaving search mode so we return immediately.
  1147.     if (key == '\r' || key == '\x1b') {
  1148.         last_match = -1;
  1149.         direction = 1;
  1150.         return;
  1151.     } else if (key == ARROW_RIGHT || key == ARROW_DOWN) {
  1152.         direction = 1;
  1153.     } else if (key == ARROW_LEFT || key == ARROW_UP) {
  1154.         if (last_match == -1) {
  1155.             // If nothing matched and the left or up arrow key was pressed
  1156.             return;
  1157.         }
  1158.         direction = -1;
  1159.     } else {
  1160.         last_match = -1;
  1161.         direction = 1;
  1162.     }
  1163.  
  1164.     int current = last_match;
  1165.     int i;
  1166.     for (i = 0; i < ec.num_rows; i++) {
  1167.         current += direction;
  1168.         if (current == -1)
  1169.             current = ec.num_rows - 1;
  1170.         else if (current == ec.num_rows)
  1171.             current = 0;
  1172.  
  1173.         editor_row* row = &ec.row[current];
  1174.         // We use strstr to check if query is a substring of the
  1175.         // current row. It returns NULL if there is no match,
  1176.         // oterwhise it returns a pointer to the matching substring.
  1177.         char* match = strstr(row -> render, query);
  1178.         if (match) {
  1179.             last_match = current;
  1180.             ec.cursor_y = current;
  1181.             ec.cursor_x = editorRowRenderXToCursorX(row, match - row -> render);
  1182.             // We set this like so to scroll to the bottom of the file so
  1183.             // that the next screen refresh will cause the matching line to
  1184.             // be at the very top of the screen.
  1185.             ec.row_offset = ec.num_rows;
  1186.  
  1187.             saved_highlight_line = current;
  1188.             saved_hightlight = malloc(row -> render_size);
  1189.             memcpy(saved_hightlight, row -> highlight, row -> render_size);
  1190.             memset(&row -> highlight[match - row -> render], HL_MATCH, strlen(query));
  1191.             break;
  1192.         }
  1193.     }
  1194. }
  1195.  
  1196. void editorSearch() {
  1197.     int saved_cursor_x = ec.cursor_x;
  1198.     int saved_cursor_y = ec.cursor_y;
  1199.     int saved_col_offset = ec.col_offset;
  1200.     int saved_row_offset = ec.row_offset;
  1201.  
  1202.     char* query = editorPrompt("Search: %s (Use ESC / Enter / Arrows)", editorSearchCallback);
  1203.  
  1204.     if (query) {
  1205.         free(query);
  1206.     // If query is NULL, that means they pressed Escape, so in that case we
  1207.     // restore the cursor previous position.
  1208.     } else {
  1209.         ec.cursor_x = saved_cursor_x;
  1210.         ec.cursor_y = saved_cursor_y;
  1211.         ec.col_offset = saved_col_offset;
  1212.         ec.row_offset = saved_row_offset;
  1213.     }
  1214. }
  1215.  
  1216. /*** Append buffer section **/
  1217.  
  1218. void abufAppend(struct a_buf* ab, const char* s, int len) {
  1219.     // Using realloc to get a block of free memory that is
  1220.     // the size of the current string + the size of the string
  1221.     // to be appended.
  1222.     char* new = realloc(ab -> buf, ab -> len + len);
  1223.  
  1224.     if (new == NULL)
  1225.         return;
  1226.  
  1227.     // Copying the string s at the end of the current data in
  1228.     // the buffer.
  1229.     memcpy(&new[ab -> len], s, len);
  1230.     ab -> buf = new;
  1231.     ab -> len += len;
  1232. }
  1233.  
  1234. void abufFree(struct a_buf* ab) {
  1235.     // Deallocating buffer.
  1236.     free(ab -> buf);
  1237. }
  1238.  
  1239. /*** Output section ***/
  1240.  
  1241. void editorScroll() {
  1242.     ec.render_x = 0;
  1243.     if (ec.cursor_y < ec.num_rows)
  1244.         ec.render_x = editorRowCursorXToRenderX(&ec.row[ec.cursor_y], ec.cursor_x);
  1245.     // The first if statement checks if the cursor is above the visible window,
  1246.     // and if so, scrolls up to where the cursor is. The second if statement checks
  1247.     // if the cursor is past the bottom of the visible window, and contains slightly
  1248.     // more complicated arithmetic because ec.row_offset refers to what's at the top
  1249.     // of the screen, and we have to get ec.screen_rows involved to talk about what's
  1250.     // at the bottom of the screen.
  1251.     if (ec.cursor_y < ec.row_offset)
  1252.         ec.row_offset = ec.cursor_y;
  1253.     if (ec.cursor_y >= ec.row_offset + ec.screen_rows)
  1254.         ec.row_offset = ec.cursor_y - ec.screen_rows + 1;
  1255.  
  1256.     if (ec.render_x < ec.col_offset)
  1257.         ec.col_offset = ec.render_x;
  1258.     if (ec.render_x >= ec.col_offset + ec.screen_cols)
  1259.         ec.col_offset = ec.render_x - ec.screen_cols + 1;
  1260. }
  1261.  
  1262. void editorDrawStatusBar(struct a_buf* ab) {
  1263.     // This switches to inverted colors.
  1264.     // NOTE:
  1265.     // The m command (Select Graphic Rendition) causes the text printed
  1266.     // after it to be printed with various possible attributes including
  1267.     // bold (1), underscore (4), blink (5), and inverted colors (7). An
  1268.     // argument of 0 clears all attributes (the default one). See
  1269.     // http://vt100.net/docs/vt100-ug/chapter3.html#SGR for more info.
  1270.     abufAppend(ab, "\x1b[7m", 4);
  1271.  
  1272.     char status[80], r_status[80];
  1273.     // Showing up to 20 characters of the filename, followed by the number of lines.
  1274.     int len = snprintf(status, sizeof(status), " Editing: %.20s %s", ec.file_name ? ec.file_name : "New file", ec.dirty ? "(modified)" : "");
  1275.     int col_size = ec.row && ec.cursor_y <= ec.num_rows - 1 ? col_size = ec.row[ec.cursor_y].size : 0;
  1276.     int r_len = snprintf(r_status, sizeof(r_status), "%d/%d lines  %d/%d cols ", ec.cursor_y + 1 > ec.num_rows ? ec.num_rows : ec.cursor_y + 1, ec.num_rows,
  1277.         ec.cursor_x + 1 > col_size ? col_size : ec.cursor_x + 1, col_size);
  1278.     if (len > ec.screen_cols)
  1279.         len = ec.screen_cols;
  1280.     abufAppend(ab, status, len);
  1281.     while (len < ec.screen_cols) {
  1282.         if (ec.screen_cols - len == r_len) {
  1283.             abufAppend(ab, r_status, r_len);
  1284.             break;
  1285.         } else {
  1286.             abufAppend(ab, " ", 1);
  1287.             len++;
  1288.         }
  1289.     }
  1290.     // This switches back to normal colors.
  1291.     abufAppend(ab, "\x1b[m", 3);
  1292.  
  1293.     abufAppend(ab, "\r\n", 2);
  1294. }
  1295.  
  1296. void editorDrawMessageBar(struct a_buf *ab) {
  1297.     // Clearing the message bar.
  1298.     abufAppend(ab, "\x1b[K", 3);
  1299.     int msg_len = strlen(ec.status_msg);
  1300.     if (msg_len > ec.screen_cols)
  1301.         msg_len = ec.screen_cols;
  1302.     // We only show the message if its less than 5 secons old, but
  1303.     // remember the screen is only being refreshed after each keypress.
  1304.     if (msg_len && time(NULL) - ec.status_msg_time < 5)
  1305.         abufAppend(ab, ec.status_msg, msg_len);
  1306. }
  1307.  
  1308. void editorDrawWelcomeMessage(struct a_buf* ab) {
  1309.     char welcome[80];
  1310.     // Using snprintf to truncate message in case the terminal
  1311.     // is too tiny to handle the entire string.
  1312.     int welcome_len = snprintf(welcome, sizeof(welcome),
  1313.         "tte %s <http://dmoral.es/>", TTE_VERSION);
  1314.     if (welcome_len > ec.screen_cols)
  1315.         welcome_len = ec.screen_cols;
  1316.     // Centering the message.
  1317.     int padding = (ec.screen_cols - welcome_len) / 2;
  1318.     // Remember that everything != 0 is true.
  1319.     if (padding) {
  1320.         abufAppend(ab, "~", 1);
  1321.         padding--;
  1322.     }
  1323.     while (padding--)
  1324.         abufAppend(ab, " ", 1);
  1325.     abufAppend(ab, welcome, welcome_len);
  1326. }
  1327.  
  1328. // The ... argument makes editorSetStatusMessage() a variadic function,
  1329. // meaning it can take any number of arguments. C's way of dealing with
  1330. // these arguments is by having you call va_start() and va_end() on a
  1331. // // value of type va_list. The last argument before the ... (in this
  1332. // case, msg) must be passed to va_start(), so that the address of
  1333. // the next arguments is known. Then, between the va_start() and
  1334. // va_end() calls, you would call va_arg() and pass it the type of
  1335. // the next argument (which you usually get from the given format
  1336. // string) and it would return the value of that argument. In
  1337. // this case, we pass msg and args to vsnprintf() and it takes care
  1338. // of reading the format string and calling va_arg() to get each
  1339. // argument.
  1340. void editorSetStatusMessage(const char* msg, ...) {
  1341.     va_list args;
  1342.     va_start(args, msg);
  1343.     vsnprintf(ec.status_msg, sizeof(ec.status_msg), msg, args);
  1344.     va_end(args);
  1345.     ec.status_msg_time = time(NULL);
  1346. }
  1347.  
  1348. void editorDrawRows(struct a_buf* ab) {
  1349.     int y;
  1350.     for (y = 0; y < ec.screen_rows; y++) {
  1351.         int file_row = y + ec.row_offset;
  1352.         if(file_row >= ec.num_rows) {
  1353.             if (ec.num_rows == 0 && y == ec.screen_rows / 3)
  1354.                 editorDrawWelcomeMessage(ab);
  1355.             else
  1356.                 abufAppend(ab, "~", 1);
  1357.         } else {
  1358.             int len = ec.row[file_row].render_size - ec.col_offset;
  1359.             // len can be a negative number, meaning the user scrolled
  1360.             // horizontally past the end of the line. In that case, we set
  1361.             // len to 0 so that nothing is displayed on that line.
  1362.             if (len < 0)
  1363.                 len = 0;
  1364.             if (len > ec.screen_cols)
  1365.                 len = ec.screen_cols;
  1366.  
  1367.             char* c = &ec.row[file_row].render[ec.col_offset];
  1368.             unsigned char* highlight = &ec.row[file_row].highlight[ec.col_offset];
  1369.             int current_color = -1;
  1370.             int j;
  1371.             for (j = 0; j < len; j++) {
  1372.                 // Displaying nonprintable characters as (A-Z, @, and ?).
  1373.                 if (iscntrl(c[j])) {
  1374.                     char sym = (c[j] <= 26) ? '@' + c[j] : '?';
  1375.                     abufAppend(ab, "\x1b[7m", 4);
  1376.                     abufAppend(ab, &sym, 1);
  1377.                     abufAppend(ab, "\x1b[m", 3);
  1378.                     if (current_color != -1) {
  1379.                         char buf[16];
  1380.                         int c_len = snprintf(buf, sizeof(buf), "\x1b[%dm", current_color);
  1381.                         abufAppend(ab, buf, c_len);
  1382.                     }
  1383.                 } else if (highlight[j] == HL_NORMAL) {
  1384.                     if (current_color != -1) {
  1385.                         abufAppend(ab, "\x1b[39m", 5);
  1386.                         current_color = -1;
  1387.                     }
  1388.                     abufAppend(ab, &c[j], 1);
  1389.                 } else {
  1390.                     int color = editorSyntaxToColor(highlight[j]);
  1391.                     // We only use escape sequence if the new color is different
  1392.                     // from the last character's color.
  1393.                     if (color != current_color) {
  1394.                         current_color = color;
  1395.                         char buf[16];
  1396.                         int c_len = snprintf(buf, sizeof(buf), "\x1b[%dm", color);
  1397.                         abufAppend(ab, buf, c_len);
  1398.                     }
  1399.  
  1400.                     abufAppend(ab, &c[j], 1);
  1401.                 }
  1402.             }
  1403.             abufAppend(ab, "\x1b[39m", 5);
  1404.         }
  1405.  
  1406.         // Redrawing each line instead of the whole screen.
  1407.         abufAppend(ab, "\x1b[K", 3);
  1408.         // Addind a new line
  1409.         abufAppend(ab, "\r\n", 2);
  1410.     }
  1411. }
  1412.  
  1413. void editorRefreshScreen() {
  1414.     editorScroll();
  1415.  
  1416.     struct a_buf ab = ABUF_INIT;
  1417.  
  1418.     // Hiding the cursor while the screen is refreshing.
  1419.     // See http://vt100.net/docs/vt100-ug/chapter3.html#S3.3.4
  1420.     // for more info.
  1421.     abufAppend(&ab, "\x1b[?25l", 6);
  1422.     abufAppend(&ab, "\x1b[H", 3);
  1423.  
  1424.     editorDrawRows(&ab);
  1425.     editorDrawStatusBar(&ab);
  1426.     editorDrawMessageBar(&ab);
  1427.  
  1428.     // Moving the cursor where it should be.
  1429.     char buf[32];
  1430.     snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (ec.cursor_y - ec.row_offset) + 1, (ec.render_x - ec.col_offset) + 1);
  1431.     abufAppend(&ab, buf, strlen(buf));
  1432.  
  1433.     // Showing again the cursor.
  1434.     abufAppend(&ab, "\x1b[?25h", 6);
  1435.  
  1436.     // Writing all content at once
  1437.     write(STDOUT_FILENO, ab.buf, ab.len);
  1438.     abufFree(&ab);
  1439. }
  1440.  
  1441. void editorClearScreen() {
  1442.     // Writing 4 bytes out to the terminal:
  1443.     // - (1 byte) \x1b : escape character
  1444.     // - (3 bytes) [2J : Clears the entire screen, see
  1445.     // http://vt100.net/docs/vt100-ug/chapter3.html#ED
  1446.     // for more info.
  1447.     write(STDOUT_FILENO, "\x1b[2J", 4);
  1448.     // Writing 3 bytes to reposition the cursor back at
  1449.     // the top-left corner, see
  1450.     // http://vt100.net/docs/vt100-ug/chapter3.html#CUP
  1451.     // for more info.
  1452.     write(STDOUT_FILENO, "\x1b[H", 3);
  1453. }
  1454.  
  1455. /*** Input section ***/
  1456.  
  1457. char* editorPrompt(char* prompt, void (*callback)(char*, int)) {
  1458.     size_t buf_size = 128;
  1459.     char* buf = malloc(buf_size);
  1460.  
  1461.     size_t buf_len = 0;
  1462.     buf[0] = '\0';
  1463.  
  1464.     while (1) {
  1465.         editorSetStatusMessage(prompt, buf);
  1466.         editorRefreshScreen();
  1467.  
  1468.         int c = editorReadKey();
  1469.         if (c == DEL_KEY || c == CTRL_KEY('h') || c == BACKSPACE) {
  1470.             if (buf_len != 0)
  1471.                 buf[--buf_len] = '\0';
  1472.         } else if (c == '\x1b') {
  1473.             editorSetStatusMessage("");
  1474.             if (callback)
  1475.                 callback(buf, c);
  1476.             free(buf);
  1477.             return NULL;
  1478.         } else if (c == '\r') {
  1479.             if (buf_len != 0) {
  1480.                 editorSetStatusMessage("");
  1481.                 if (callback)
  1482.                     callback(buf, c);
  1483.                 return buf;
  1484.             }
  1485.         } else if (!iscntrl(c) && isprint(c)) {
  1486.             if (buf_len == buf_size - 1) {
  1487.                 buf_size *= 2;
  1488.                 buf = realloc(buf, buf_size);
  1489.             }
  1490.             buf[buf_len++] = c;
  1491.             buf[buf_len] = '\0';
  1492.         }
  1493.  
  1494.         if (callback)
  1495.             callback(buf, c);
  1496.     }
  1497. }
  1498.  
  1499. void editorMoveCursor(int key) {
  1500.     editor_row* row = (ec.cursor_y >= ec.num_rows) ? NULL : &ec.row[ec.cursor_y];
  1501.  
  1502.     switch (key) {
  1503.         case ARROW_LEFT:
  1504.             if (ec.cursor_x != 0)
  1505.                 ec.cursor_x--;
  1506.             // If <- is pressed, move to the end of the previous line
  1507.             else if (ec.cursor_y > 0) {
  1508.                 ec.cursor_y--;
  1509.                 ec.cursor_x = ec.row[ec.cursor_y].size;
  1510.             }
  1511.             break;
  1512.         case ARROW_RIGHT:
  1513.             if (row && ec.cursor_x < row -> size)
  1514.                 ec.cursor_x++;
  1515.             // If -> is pressed, move to the start of the next line
  1516.             else if (row && ec.cursor_x == row -> size) {
  1517.                 ec.cursor_y++;
  1518.                 ec.cursor_x = 0;
  1519.             }
  1520.             break;
  1521.         case ARROW_UP:
  1522.             if (ec.cursor_y != 0)
  1523.                 ec.cursor_y--;
  1524.             break;
  1525.         case ARROW_DOWN:
  1526.             if (ec.cursor_y < ec.num_rows)
  1527.                 ec.cursor_y++;
  1528.             break;
  1529.     }
  1530.  
  1531.     // Move cursor_x if it ends up past the end of the line it's on
  1532.     row = (ec.cursor_y >= ec.num_rows) ? NULL : &ec.row[ec.cursor_y];
  1533.     int row_len = row ? row -> size : 0;
  1534.     if (ec.cursor_x > row_len)
  1535.         ec.cursor_x = row_len;
  1536. }
  1537.  
  1538. void editorProcessKeypress() {
  1539.     static int quit_times = TTE_QUIT_TIMES;
  1540.  
  1541.     int c = editorReadKey();
  1542.  
  1543.     switch (c) {
  1544.         case '\r': // Enter key
  1545.             editorInsertNewline();
  1546.             break;
  1547.         case CTRL_KEY('q'):
  1548.             if (ec.dirty && quit_times > 0) {
  1549.                 editorSetStatusMessage("Warning! File has unsaved changes. Press Ctrl-Q %d more time%s to quit", quit_times, quit_times > 1 ? "s" : "");
  1550.                 quit_times--;
  1551.                 return;
  1552.             }
  1553.             editorClearScreen();
  1554.             consoleBufferClose();
  1555.             exit(0);
  1556.             break;
  1557.         case CTRL_KEY('s'):
  1558.             editorSave();
  1559.             break;
  1560.         case CTRL_KEY('e'):
  1561.             if (ec.cursor_y > 0 && ec.cursor_y <= ec.num_rows - 1)
  1562.                 editorFlipRow(1);
  1563.             break;
  1564.         case CTRL_KEY('d'):
  1565.             if (ec.cursor_y < ec.num_rows - 1)
  1566.             editorFlipRow(-1);
  1567.             break;
  1568.         case CTRL_KEY('x'):
  1569.             if (ec.cursor_y < ec.num_rows)
  1570.             editorCut();
  1571.             break;
  1572.         case CTRL_KEY('c'):
  1573.             if (ec.cursor_y < ec.num_rows)
  1574.             editorCopy(0);
  1575.             break;
  1576.         case CTRL_KEY('v'):
  1577.             editorPaste();
  1578.             break;
  1579.         case CTRL_KEY('p'):
  1580.             consoleBufferClose();
  1581.             kill(0, SIGTSTP);
  1582.         case ARROW_UP:
  1583.         case ARROW_DOWN:
  1584.         case ARROW_LEFT:
  1585.         case ARROW_RIGHT:
  1586.             editorMoveCursor(c);
  1587.             break;
  1588.         case PAGE_UP:
  1589.         case PAGE_DOWN:
  1590.             { // You can't declare variables directly inside a switch statement.
  1591.                 if (c == PAGE_UP)
  1592.                     ec.cursor_y = ec.row_offset;
  1593.                 else if (c == PAGE_DOWN)
  1594.                     ec.cursor_y = ec.row_offset + ec.screen_rows - 1;
  1595.  
  1596.                 int times = ec.screen_rows;
  1597.                 while (times--)
  1598.                     editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
  1599.             }
  1600.             break;
  1601.         case HOME_KEY:
  1602.             ec.cursor_x = 0;
  1603.             break;
  1604.         case END_KEY:
  1605.             if (ec.cursor_y < ec.num_rows)
  1606.                 ec.cursor_x = ec.row[ec.cursor_y].size;
  1607.             break;
  1608.         case CTRL_KEY('f'):
  1609.             editorSearch();
  1610.             break;
  1611.         case BACKSPACE:
  1612.         case CTRL_KEY('h'):
  1613.         case DEL_KEY:
  1614.             if (c == DEL_KEY)
  1615.                 editorMoveCursor(ARROW_RIGHT);
  1616.             editorDelChar();
  1617.             break;
  1618.         case CTRL_KEY('l'):
  1619.         case '\x1b': // Escape key
  1620.             break;
  1621.         default:
  1622.             editorInsertChar(c);
  1623.             break;
  1624.     }
  1625.  
  1626.     quit_times = TTE_QUIT_TIMES;
  1627. }
  1628.  
  1629. /*** Init section ***/
  1630.  
  1631. void initEditor() {
  1632.     ec.cursor_x = 0;
  1633.     ec.cursor_y = 0;
  1634.     ec.render_x = 0;
  1635.     ec.row_offset = 0;
  1636.     ec.col_offset = 0;
  1637.     ec.num_rows = 0;
  1638.     ec.row = NULL;
  1639.     ec.dirty = 0;
  1640.     ec.file_name = NULL;
  1641.     ec.status_msg[0] = '\0';
  1642.     ec.status_msg_time = 0;
  1643.     ec.copied_char_buffer = NULL;
  1644.     ec.syntax = NULL;
  1645.  
  1646.     editorUpdateWindowSize();
  1647.     // The SIGWINCH signal is sent to a process when its controlling
  1648.     // terminal changes its size (a window change).
  1649.     signal(SIGWINCH, editorHandleSigwinch);
  1650.     // The SIGCONT signal instructs the operating system to continue
  1651.     // (restart) a process previously paused by the SIGSTOP or SIGTSTP
  1652.     // signal.
  1653.     signal(SIGCONT, editorHandleSigcont);
  1654. }
  1655.  
  1656. void printHelp() {
  1657.     printf("Usage: tte [OPTIONS] [FILE]\n\n");
  1658.     printf("\nKEYBINDINGS\n-----------\n\n");
  1659.     printf("Keybinding\t\tAction\n\n");
  1660.     printf("Ctrl-Q    \t\tExit\n");
  1661.     printf("Ctrl-S    \t\tSave\n");
  1662.     printf("Ctrl-F    \t\tSearch. Esc, enter and arrows to interact once searching\n");
  1663.     printf("Ctrl-E    \t\tFlip line upwards\n");
  1664.     printf("Ctrl-D    \t\tFlip line downwards\n");
  1665.     printf("Ctrl-C    \t\tCopy line\n");
  1666.     printf("Ctrl-X    \t\tCut line\n");
  1667.     printf("Ctrl-V    \t\tPaste line\n");
  1668.     printf("Ctrl-P    \t\tPause tte (type \"fg\" to resume)\n");
  1669.  
  1670.     printf("\n\nOPTIONS\n-------\n\n");
  1671.     printf("Option        \t\tAction\n\n");
  1672.     printf("-h | --help   \t\tPrints the help\n");
  1673.     printf("-v | --version\t\tPrints the version of tte\n");
  1674.  
  1675.     printf("\n\nFor now, usage of ISO 8859-1 is recommended.\n");
  1676. }
  1677.  
  1678. // 1 if editor should open, 0 otherwise, -1 if the program should exit
  1679. int handleArgs(int argc, char* argv[]) {
  1680.     if (argc == 1)
  1681.         return 0;
  1682.  
  1683.     if (argc >= 2) {
  1684.         if (strncmp("-h", argv[1], 2) == 0 || strncmp("--help", argv[1], 6) == 0) {
  1685.             printHelp();
  1686.             return -1;
  1687.         } else if(strncmp("-v", argv[1], 2) == 0 || strncmp("--version", argv[1], 9) == 0) {
  1688.             printf("tte - version %s\n", TTE_VERSION);
  1689.             return -1;
  1690.         }
  1691.     }
  1692.  
  1693.     return 1;
  1694. }
  1695.  
  1696. int main(int argc, char* argv[]) {
  1697.     initEditor();
  1698.     int arg_response = handleArgs(argc, argv);
  1699.     if (arg_response == 1)
  1700.         editorOpen(argv[1]);
  1701.     else if (arg_response == -1)
  1702.         return 0;
  1703.     enableRawMode();
  1704.  
  1705.     editorSetStatusMessage(" Ctrl-Q to quit | Ctrl-S to save | (tte -h | --help for more info)");
  1706.  
  1707.     while (1) {
  1708.         editorRefreshScreen();
  1709.         editorProcessKeypress();
  1710.     }
  1711.  
  1712.     return 0;
  1713. }
  1714.