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/*
* Copyright (c) 2012 Stefano Sabatini
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <unistd.h> /* getopt */
#include "libavutil/eval.h"
/**
* @file
* simple arithmetic expression evaluator
*/
static void usage(void)
{
printf("Simple expression evalutor, please *don't* turn me to a feature-complete language interpreter\n");
printf("usage: ffeval [OPTIONS]\n");
printf("\n"
"Options:\n"
"-e echo each input line on output\n"
"-h print this help\n"
"-i INFILE set INFILE as input file, stdin if omitted\n"
"-o OUTFILE set OUTFILE as output file, stdout if omitted\n"
"-p PROMPT set output prompt\n");
}
#define MAX_BLOCK_SIZE SIZE_MAX
int main(int argc, char **argv)
{
size_t buf_size = 256;
char *buf = av_malloc(buf_size);
const char *outfilename = NULL, *infilename = NULL;
FILE *outfile = NULL, *infile = NULL;
const char *prompt = "=> ";
int count = 0, echo = 0;
char c;
av_max_alloc(MAX_BLOCK_SIZE);
while ((c = getopt(argc, argv, "ehi:o:p:")) != -1) {
switch (c) {
case 'e':
echo = 1;
break;
case 'h':
usage();
return 0;
case 'i':
infilename = optarg;
break;
case 'o':
outfilename = optarg;
break;
case 'p':
prompt = optarg;
break;
case '?':
return 1;
}
}
if (!infilename || !strcmp(infilename, "-"))
infilename = "/dev/stdin";
infile = fopen(infilename, "r");
if (!infile) {
fprintf(stderr, "Impossible to open input file '%s': %s\n", infilename, strerror(errno));
return 1;
}
if (!outfilename || !strcmp(outfilename, "-"))
outfilename = "/dev/stdout";
outfile = fopen(outfilename, "w");
if (!outfile) {
fprintf(stderr, "Impossible to open output file '%s': %s\n", outfilename, strerror(errno));
return 1;
}
while ((c = fgetc(infile)) != EOF) {
if (c == '\n') {
double d;
buf[count] = 0;
if (buf[0] != '#') {
av_expr_parse_and_eval(&d, buf,
NULL, NULL,
NULL, NULL, NULL, NULL, NULL, 0, NULL);
if (echo)
fprintf(outfile, "%s ", buf);
fprintf(outfile, "%s%f\n", prompt, d);
}
count = 0;
} else {
if (count >= buf_size-1) {
if (buf_size == MAX_BLOCK_SIZE) {
av_log(NULL, AV_LOG_ERROR, "Memory allocation problem, "
"max block size '%zd' reached\n", MAX_BLOCK_SIZE);
return 1;
}
buf_size = FFMIN(buf_size, MAX_BLOCK_SIZE / 2) * 2;
buf = av_realloc_f((void *)buf, buf_size, 1);
if (!buf) {
av_log(NULL, AV_LOG_ERROR, "Memory allocation problem occurred\n");
return 1;
}
}
buf[count++] = c;
}
}
av_free(buf);
return 0;
}
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