/* write.c -- write bytes to an output device.
*
* Copyright (c) 1995 Cygnus Support
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
#include <errno.h>
#include <unistd.h>
#include <alloca.h>
#include "io.h"
#undef erro
extern int errno;
#if 0
#define PAD_SIZE 512
static int zero_pad(int handle ) /* 09-jan-95 */
/*******************************/
{
int rc;
long curPos, eodPos;
long bytesToWrite;
unsigned writeAmt;
char zeroBuf[PAD_SIZE];
// Pad with zeros due to lseek() past EOF (POSIX)
curPos = lseek( handle, 0L, SEEK_CUR ); /* current offset */
if( curPos == -1 )
return( -1 );
eodPos = lseek( handle, 0L, SEEK_END ); /* end of data offset */
if( eodPos == -1 )
return( -1 );
if( curPos > eodPos ) {
bytesToWrite = curPos - eodPos; /* amount to pad by */
if( bytesToWrite > 0 ) { /* only write if needed */
memset( zeroBuf
, 0x00, PAD_SIZE
); /* zero out a buffer */ do { /* loop until done */
if( bytesToWrite > PAD_SIZE )
writeAmt = 512;
else
writeAmt = (unsigned)bytesToWrite;
rc = _write_r(ptr, handle, zeroBuf, writeAmt );
if( rc < 0 )
return( rc );
bytesToWrite -= writeAmt; /* more bytes written */
} while( bytesToWrite != 0 );
}
} else {
curPos = _lseek_r( ptr, handle, curPos, SEEK_SET );
if( curPos == -1 ) {
return( -1 );
}
}
return( 0 ); /* return success code */
}
#endif
static int os_write(int handle, const void *buffer, unsigned len, unsigned *amt )
{
__io_handle *ioh;
int rc;
rc = 0;
*amt = 0;
ioh = &__io_tab[handle];
rc = ioh->write(ioh->name,(const void*)buffer,ioh->offset,len,amt);
ioh->offset+= *amt;
if( *amt && *amt != len )
{
rc = ENOSPC;
errno = rc;
}
return( rc );
}
/*
* write -- write bytes to the serial port. Ignore fd, since
* stdout and stderr are the same. Since we have no filesystem,
* open will only return an error.
*/
ssize_t write(int fd, const void *buffer, size_t cnt)
{
_ssize_t ret;
unsigned int iomode_flags;
unsigned len_written, i, j;
int rc2;
char *buf;
__io_handle *ioh;
if( (fd < 0) || (fd >=64) )
{
errno = EBADF;
return -1;
};
ioh = &__io_tab[fd];
iomode_flags = ioh->mode;
if( iomode_flags == 0 )
{
errno = EBADF;
return( -1 );
}
if( !(iomode_flags & _WRITE) )
{
errno = EACCES ;
return( -1 );
}
if( (iomode_flags & _APPEND) && !(iomode_flags & _ISTTY) )
{
ioh->offset = lseek(fd, 0L, SEEK_END ); /* end of data offset */
}
len_written = 0;
rc2 = 0;
// Pad the file with zeros if necessary
if( iomode_flags & _FILEEXT )
{
// turn off file extended flag
ioh->mode = iomode_flags & (~_FILEEXT);
// It is not required to pad a file with zeroes on an NTFS file system;
// unfortunately it is required on FAT (and probably FAT32). (JBS)
// rc2 = zero_pad( ptr, fd );
}
if( rc2 == 0 )
{
if( iomode_flags & _BINARY ) { /* if binary mode */
rc2 = os_write(fd, buffer, cnt, &len_written );
/* end of binary mode part */
} else { /* text mode */
int buf_size = 512;
buf = (char*)alloca( buf_size );
j = 0;
for( i = 0; i < cnt; )
{
if( ((const char*)buffer)[i] == '\n' )
{
buf[j] = '\r';
++j;
if( j == buf_size )
{
rc2 = os_write(fd, buf, buf_size, &j );
if( rc2 == -1 )
break;
len_written += j;
if( rc2 == ENOSPC )
break;
len_written = i;
j = 0;
}
}
buf[j] = ((const char*)buffer)[i];
++i;
++j;
if( j == buf_size ) {
rc2 = os_write(fd, buf, buf_size, &j );
if( rc2 == -1 )
break;
len_written += j;
if( rc2 == ENOSPC )
break;
len_written = i;
j = 0;
}
}
if( j ) {
rc2 = os_write(fd, buf, j, &i );
if( rc2 == ENOSPC ) {
len_written += i;
} else {
len_written = cnt;
}
}
/* end of text mode part */
}
}
if( rc2 == -1 ) {
return( rc2 );
} else {
return( len_written );
}
return 0;
}