[FFmpeg-devel] [PATCH] tools: add ffescape utility

[Stefano Sabatini]

---
 libavutil/Makefile |    2 +-
 tools/ffescape.c   |  175 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 176 insertions(+), 1 deletions(-)
 create mode 100644 tools/ffescape.c

diff --git a/libavutil/Makefile b/libavutil/Makefile
index 841eec5..8d9996d 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -129,6 +129,6 @@ TESTPROGS = adler32                                                     \
 
 TESTPROGS-$(HAVE_LZO1X_999_COMPRESS) += lzo
 
-TOOLS = ffeval
+TOOLS = ffeval ffescape
 
 $(SUBDIR)lzo-test$(EXESUF): ELIBS = -llzo2
diff --git a/tools/ffescape.c b/tools/ffescape.c
new file mode 100644
index 0000000..42e3370
--- /dev/null
+++ b/tools/ffescape.c
@@ -0,0 +1,175 @@
+/*
+ * 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"
+           "-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 MAX_BLOCK_SIZE SIZE_MAX
+
+#define WHITESPACES " \n\t"
+
+static char *escape(const char *src, const char *special_chars)
+{
+    AVBPrint dst;
+    char *ret;
+
+    av_bprint_init(&dst, 1, AV_BPRINT_SIZE_UNLIMITED);
+    for (; *src; src++) {
+        if ((special_chars && strchr(special_chars, *src)) ||
+            strchr("'\\" WHITESPACES, *src))
+            av_bprintf(&dst, "\\%c", *src);
+        else
+            av_bprint_chars(&dst, *src, 1);
+    }
+    av_bprint_finalize(&dst, &ret);
+    return ret;
+}
+
+int main(int argc, char **argv)
+{
+    size_t src_buf_size = 256;
+    char *src_buf = av_malloc(src_buf_size), *dst_buf = NULL;
+    const char *outfilename = NULL, *infilename = NULL;
+    FILE *outfile = NULL, *infile = NULL;
+    const char *prompt = "=> ";
+    int level = 1;
+    int count = 0, echo = 0;
+    char *special_chars = NULL;
+    char c;
+
+    av_max_alloc(MAX_BLOCK_SIZE);
+
+    while ((c = getopt(argc, argv, "ehi:l:o: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 'o':
+            outfilename = optarg;
+            break;
+        case 'p':
+            prompt = optarg;
+            break;
+        case 's':
+            special_chars = 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;
+    }
+
+    /* grab the input and store it in buf */
+    while ((c = fgetc(infile)) != EOF) {
+        if (count >= src_buf_size-1) {
+            if (src_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;
+            }
+            src_buf_size = FFMIN(src_buf_size, MAX_BLOCK_SIZE / 2) * 2;
+            src_buf = av_realloc_f((void *)src_buf, src_buf_size, 1);
+            if (!src_buf) {
+                av_log(NULL, AV_LOG_ERROR, "Memory allocation problem occurred\n");
+                return 1;
+            }
+        }
+        src_buf[count++] = c;
+    }
+    src_buf[count] = 0;
+
+    if (echo)
+        fprintf(outfile, "%s ", src_buf);
+
+    /* escape */
+    dst_buf = src_buf;
+    while (level--) {
+        dst_buf = escape(src_buf, special_chars);
+        av_free(src_buf);
+        src_buf = dst_buf;
+    }
+
+    fprintf(outfile, "%s%s", prompt, dst_buf);
+    av_free(dst_buf);
+    return 0;
+}
-- 
1.7.5.4