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ffeval.c
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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%f (%s)\n", prompt, d, 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 }
#define NULL
Definition: coverity.c:32
memory handling functions
static void usage(void)
Definition: ffeval.c:38
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:722
GLsizei count
Definition: opengl_enc.c:109
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
#define GROW_ARRAY()
static int getopt(int argc, char *argv[], char *opts)
Definition: getopt.c:41
void * buf
Definition: avisynth_c.h:553
static double c[64]
static char * optarg
Definition: getopt.c:39
#define av_free(p)
int main(int argc, char **argv)
Definition: ffeval.c:51
FILE * outfile
Definition: audiogen.c:96
simple arithmetic expression evaluator