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  1. /*
  2.  * Copyright (c) 2012 Stefano Sabatini
  3.  *
  4.  * This file is part of FFmpeg.
  5.  *
  6.  * FFmpeg is free software; you can redistribute it and/or
  7.  * modify it under the terms of the GNU Lesser General Public
  8.  * License as published by the Free Software Foundation; either
  9.  * version 2.1 of the License, or (at your option) any later version.
  10.  *
  11.  * FFmpeg is distributed in the hope that it will be useful,
  12.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14.  * Lesser General Public License for more details.
  15.  *
  16.  * You should have received a copy of the GNU Lesser General Public
  17.  * License along with FFmpeg; if not, write to the Free Software
  18.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19.  */
  20.  
  21. #include "config.h"
  22. #if HAVE_UNISTD_H
  23. #include <unistd.h>             /* getopt */
  24. #endif
  25.  
  26. #include "libavutil/eval.h"
  27. #include "libavutil/mem.h"
  28.  
  29. #if !HAVE_GETOPT
  30. #include "compat/getopt.c"
  31. #endif
  32.  
  33. /**
  34.  * @file
  35.  * simple arithmetic expression evaluator
  36.  */
  37.  
  38. static void usage(void)
  39. {
  40.     printf("Simple expression evalutor, please *don't* turn me to a feature-complete language interpreter\n");
  41.     printf("usage: ffeval [OPTIONS]\n");
  42.     printf("\n"
  43.            "Options:\n"
  44.            "-e                echo each input line on output\n"
  45.            "-h                print this help\n"
  46.            "-i INFILE         set INFILE as input file, stdin if omitted\n"
  47.            "-o OUTFILE        set OUTFILE as output file, stdout if omitted\n"
  48.            "-p PROMPT         set output prompt\n");
  49. }
  50.  
  51. int main(int argc, char **argv)
  52. {
  53.     int buf_size = 0;
  54.     char *buf = NULL;
  55.     const char *outfilename = NULL, *infilename = NULL;
  56.     FILE *outfile = NULL, *infile = NULL;
  57.     const char *prompt = "=> ";
  58.     int count = 0, echo = 0;
  59.     int c;
  60.  
  61. #define GROW_ARRAY()                                                    \
  62.     do {                                                                \
  63.         if (!av_dynarray2_add((void **)&buf, &buf_size, 1, NULL)) {     \
  64.             av_log(NULL, AV_LOG_ERROR,                                  \
  65.                    "Memory allocation problem occurred\n");             \
  66.             return 1;                                                   \
  67.         }                                                               \
  68.     } while (0)
  69.  
  70.     GROW_ARRAY();
  71.     while ((c = getopt(argc, argv, "ehi:o:p:")) != -1) {
  72.         switch (c) {
  73.         case 'e':
  74.             echo = 1;
  75.             break;
  76.         case 'h':
  77.             usage();
  78.             return 0;
  79.         case 'i':
  80.             infilename = optarg;
  81.             break;
  82.         case 'o':
  83.             outfilename = optarg;
  84.             break;
  85.         case 'p':
  86.             prompt = optarg;
  87.             break;
  88.         case '?':
  89.             return 1;
  90.         }
  91.     }
  92.  
  93.     if (!infilename || !strcmp(infilename, "-")) {
  94.         infilename = "stdin";
  95.         infile = stdin;
  96.     } else {
  97.         infile = fopen(infilename, "r");
  98.     }
  99.     if (!infile) {
  100.         fprintf(stderr, "Impossible to open input file '%s': %s\n", infilename, strerror(errno));
  101.         return 1;
  102.     }
  103.  
  104.     if (!outfilename || !strcmp(outfilename, "-")) {
  105.         outfilename = "stdout";
  106.         outfile = stdout;
  107.     } else {
  108.         outfile = fopen(outfilename, "w");
  109.     }
  110.     if (!outfile) {
  111.         fprintf(stderr, "Impossible to open output file '%s': %s\n", outfilename, strerror(errno));
  112.         return 1;
  113.     }
  114.  
  115.     while ((c = fgetc(infile)) != EOF) {
  116.         if (c == '\n') {
  117.             double d;
  118.  
  119.             buf[count] = 0;
  120.             if (buf[0] != '#') {
  121.                 int ret = av_expr_parse_and_eval(&d, buf,
  122.                                                  NULL, NULL,
  123.                                                  NULL, NULL, NULL, NULL, NULL, 0, NULL);
  124.                 if (echo)
  125.                     fprintf(outfile, "%s ", buf);
  126.                 if (ret >= 0) fprintf(outfile, "%s%f\n", prompt, d);
  127.                 else          fprintf(outfile, "%s%s\n", prompt, av_err2str(ret));
  128.             }
  129.             count = 0;
  130.         } else {
  131.             if (count >= buf_size-1)
  132.                 GROW_ARRAY();
  133.             buf[count++] = c;
  134.         }
  135.     }
  136.  
  137.     av_free(buf);
  138.     return 0;
  139. }
  140.