/* * 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 "config.h"#if HAVE_UNISTD_H#include <unistd.h>             /* getopt */#endif #include "libavutil/eval.h"#include "libavutil/mem.h" #if !HAVE_GETOPT#include "compat/getopt.c"#endif /** * @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");} int main(int argc, char **argv){    int buf_size = 0;    char *buf = NULL;    const char *outfilename = NULL, *infilename = NULL;    FILE *outfile = NULL, *infile = NULL;    const char *prompt = "=> ";    int count = 0, echo = 0;    int c; #define GROW_ARRAY()                                                    \    do {                                                                \        if (!av_dynarray2_add((void **)&buf, &buf_size, 1, NULL)) {     \            av_log(NULL, AV_LOG_ERROR,                                  \                   "Memory allocation problem occurred\n");             \            return 1;                                                   \        }                                                               \    } while (0)     GROW_ARRAY();    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 = "stdin";        infile = stdin;    } else {        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 = "stdout";        outfile = stdout;    } else {        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] != '#') {                int ret = av_expr_parse_and_eval(&d, buf,                                                 NULL, NULL,                                                 NULL, NULL, NULL, NULL, NULL, 0, NULL);                if (echo)                    fprintf(outfile, "%s ", buf);                if (ret >= 0) fprintf(outfile, "%s%f\n", prompt, d);                else          fprintf(outfile, "%s%f (%s)\n", prompt, d, av_err2str(ret));            }            count = 0;        } else {            if (count >= buf_size-1)                GROW_ARRAY();            buf[count++] = c;        }    }     av_free(buf);    return 0;}