/* * 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; }