tools: add ffescape utility

1 files changed, 233 insertions, 0 deletions

diff --git a/tools/ffescape.c b/tools/ffescape.c
new file mode 100644
index 0000000..d777fe4
--- /dev/null
+++ b/tools/ffescape.c
@@ -0,0 +1,233 @@
+/*
+ * 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/log.h"
+#include "libavutil/bprint.h"
+
+#if !HAVE_GETOPT
+#include "compat/getopt.c"
+#endif
+
+/**
+ * @file
+ * escaping utility
+ */
+
+static void usage(void)
+{
+    printf("Escape an input string, adopting the av_get_token() escaping logic\n");
+    printf("usage: ffescape [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"
+           "-l LEVEL          set the number of escaping levels, 1 if omitted\n"
+           "-m ESCAPE_MODE    select escape mode between 'full', 'lazy', 'quote', default is 'lazy'\n"
+           "-o OUTFILE        set OUTFILE as output file, stdout if omitted\n"
+           "-p PROMPT         set output prompt, is '=> ' by default\n"
+           "-s SPECIAL_CHARS  set the list of special characters\n");
+}
+
+#define WHITESPACES " \n\t"
+
+enum EscapeMode {
+    ESCAPE_MODE_FULL,
+    ESCAPE_MODE_LAZY,
+    ESCAPE_MODE_QUOTE,
+};
+
+static int escape(char **dst, const char *src, const char *special_chars,
+                  enum EscapeMode mode)
+{
+    AVBPrint dstbuf;
+
+    av_bprint_init(&dstbuf, 1, AV_BPRINT_SIZE_UNLIMITED);
+
+    switch (mode) {
+    case ESCAPE_MODE_FULL:
+    case ESCAPE_MODE_LAZY:
+        /* \-escape characters */
+
+        if (mode == ESCAPE_MODE_LAZY && strchr(WHITESPACES, *src))
+            av_bprintf(&dstbuf, "\\%c", *src++);
+
+        for (; *src; src++) {
+            if ((special_chars && strchr(special_chars, *src)) ||
+                strchr("'\\", *src) ||
+                (mode == ESCAPE_MODE_FULL && strchr(WHITESPACES, *src)))
+                av_bprintf(&dstbuf, "\\%c", *src);
+            else
+                av_bprint_chars(&dstbuf, *src, 1);
+        }
+
+        if (mode == ESCAPE_MODE_LAZY && strchr(WHITESPACES, dstbuf.str[dstbuf.len-1])) {
+            char c = dstbuf.str[dstbuf.len-1];
+            dstbuf.str[dstbuf.len-1] = '\\';
+            av_bprint_chars(&dstbuf, c, 1);
+        }
+        break;
+
+    case ESCAPE_MODE_QUOTE:
+        /* enclose between '' the string */
+        av_bprint_chars(&dstbuf, '\'', 1);
+        for (; *src; src++) {
+            if (*src == '\'')
+                av_bprintf(&dstbuf, "'\\''");
+            else
+                av_bprint_chars(&dstbuf, *src, 1);
+        }
+        av_bprint_chars(&dstbuf, '\'', 1);
+        break;
+
+    default:
+        /* unknown escape mode */
+        return AVERROR(EINVAL);
+    }
+
+    if (!av_bprint_is_complete(&dstbuf)) {
+        av_bprint_finalize(&dstbuf, NULL);
+        return AVERROR(ENOMEM);
+    } else {
+        av_bprint_finalize(&dstbuf, dst);
+        return 0;
+    }
+}
+
+int main(int argc, char **argv)
+{
+    AVBPrint src;
+    char *src_buf, *dst_buf;
+    const char *outfilename = NULL, *infilename = NULL;
+    FILE *outfile = NULL, *infile = NULL;
+    const char *prompt = "=> ";
+    enum EscapeMode escape_mode = ESCAPE_MODE_LAZY;
+    int level = 1;
+    int echo = 0;
+    char *special_chars = NULL;
+    int c;
+
+    while ((c = getopt(argc, argv, "ehi:l:o:m:p:s:")) != -1) {
+        switch (c) {
+        case 'e':
+            echo = 1;
+            break;
+        case 'h':
+            usage();
+            return 0;
+        case 'i':
+            infilename = optarg;
+            break;
+        case 'l':
+        {
+            char *tail;
+            long int li = strtol(optarg, &tail, 10);
+            if (*tail || li > INT_MAX || li < 0) {
+                av_log(NULL, AV_LOG_ERROR,
+                        "Invalid value '%s' for option -l, argument must be a non negative integer\n",
+                        optarg);
+                return 1;
+            }
+            level = li;
+            break;
+        }
+        case 'm':
+            if      (!strcmp(optarg, "full"))  escape_mode = ESCAPE_MODE_FULL;
+            else if (!strcmp(optarg, "lazy"))  escape_mode = ESCAPE_MODE_LAZY;
+            else if (!strcmp(optarg, "quote")) escape_mode = ESCAPE_MODE_QUOTE;
+            else {
+                av_log(NULL, AV_LOG_ERROR,
+                       "Invalid value '%s' for option -m, "
+                       "valid arguments are 'full', 'lazy', 'quote'\n", optarg);
+                return 1;
+            }
+            break;
+        case 'o':
+            outfilename = optarg;
+            break;
+        case 'p':
+            prompt = optarg;
+            break;
+        case 's':
+            special_chars = optarg;
+            break;
+        case '?':
+            return 1;
+        }
+    }
+
+    if (!infilename || !strcmp(infilename, "-")) {
+        infilename = "stdin";
+        infile = stdin;
+    } else {
+        infile = fopen(infilename, "r");
+    }
+    if (!infile) {
+        av_log(NULL, AV_LOG_ERROR, "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) {
+        av_log(NULL, AV_LOG_ERROR, "Impossible to open output file '%s': %s\n", outfilename, strerror(errno));
+        return 1;
+    }
+
+    /* grab the input and store it in src */
+    av_bprint_init(&src, 1, AV_BPRINT_SIZE_UNLIMITED);
+    while ((c = fgetc(infile)) != EOF)
+        av_bprint_chars(&src, c, 1);
+    av_bprint_chars(&src, 0, 1);
+
+    if (!av_bprint_is_complete(&src)) {
+        av_log(NULL, AV_LOG_ERROR, "Could not allocate a buffer for the source string\n");
+        av_bprint_finalize(&src, NULL);
+        return 1;
+    }
+    av_bprint_finalize(&src, &src_buf);
+
+    if (echo)
+        fprintf(outfile, "%s", src_buf);
+
+    /* escape */
+    dst_buf = src_buf;
+    while (level--) {
+        if (escape(&dst_buf, src_buf, special_chars, escape_mode) < 0) {
+            av_log(NULL, AV_LOG_ERROR, "Could not escape string\n");
+            return 1;
+        }
+        av_free(src_buf);
+        src_buf = dst_buf;
+    }
+
+    fprintf(outfile, "%s%s", prompt, dst_buf);
+    av_free(dst_buf);
+    return 0;
+}