I've written a useful convienience routine that I think would be
useful for gnulib. It's called str_quotify, and it converts a char
pointer and a length into a C-style backslash quoted string. It's
very useful for debugging output and such.
I'm happy to assign copyright to the FSF.
I've included the .c and the .h files.
/* str_quotify.h -- create a C backslashed escaped string
Copyright (C) 2007 by Mark Atwood <[EMAIL PROTECTED]>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#ifndef _INCLUDE_STRQUOTIFY
#define _INCLUDE_STRQUOTIFY
#ifdef __cplusplus
extern "C" {
#endif
/* Copy src into dst, converting it a C style backslashed escaped
string. All control characters, high bit characters, the ASCII
NULL, and all whitespace except the space character itself will be
converted. The backslash and the quotation characters will be
escaped as well. If the dst buffer isn't long enough, as much as
will fit will be done. The dst buffer will be null terminated,
so it can safely be treated as a C string. The dst buffer will
also be returned.
*/
char *str_quotify (char *dst, size_t dstlen,
const char *src, size_t srclen);
#ifdef __cplusplus
}
#endif
#endif /* ndef _INCLUDE_STRQUOTIFY */
/* str_quotify.c -- create a C backslashed escaped string
Copyright (C) 2007 by Mark Atwood <[EMAIL PROTECTED]>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <string.h>
#include <ctype.h>
#include "str_quotify.h"
char *str_quotify (char *dst, size_t dstlen,
const char *src, size_t srclen)
{
static char hexit[] = { '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
int i; /* index down the dst */
int n; /* index down the src */
for (i=0,n=0; n<srclen; n++) {
/* Worst case, need 5 dst bytes for the next src byte.
backslash x hexit hexit null */
if ((dstlen - i) < 5) { dst[i] = '\0'; return dst; }
if (src[n] == 0x00) { /* null */
dst[i++] = '\\'; dst[i++] = '0';
} else if (src[n] == 0x07) { /* bell */
dst[i++] = '\\'; dst[i++] = 'a';
} else if (src[n] == 0x08) { /* backspace */
dst[i++] = '\\'; dst[i++] = 'b';
} else if (src[n] == 0x09) { /* horiz tab */
dst[i++] = '\\'; dst[i++] = 't';
} else if (src[n] == 0x0a) { /* line feed */
dst[i++] = '\\'; dst[i++] = 'n';
} else if (src[n] == 0x0b) { /* vert tab */
dst[i++] = '\\'; dst[i++] = 'v';
} else if (src[n] == 0x0c) { /* formfeed */
dst[i++] = '\\'; dst[i++] = 'f';
} else if (src[n] == 0x0d) { /* carrage return */
dst[i++] = '\\'; dst[i++] = 'r';
} else if (src[n] == 0x22) { /* quotation mark */
dst[i++] = '\\'; dst[i++] = 0x22;
} else if (src[n] == 0x5C) { /* backslash */
dst[i++] = '\\'; dst[i++] = 0x5C;
} else if (src[n] == ' ') {
dst[i++] = ' ';
} else if (isgraph(src[n])) {
dst[i++] = src[n];
} else {
dst[i++] = '\\';
dst[i++] = 'x';
dst[i++] = hexit[(src[n] >> 8) & 0x0f];
dst[i++] = hexit[src[n] & 0x0f];
}
dst[i] = '\0';
}
return dst;
}
#ifdef STRQUOTIFY_DEMO
#include <stdio.h>
#include <string.h>
#include <unistd.h>
int main (int argc, char *argv[])
{
switch (getopt(argc, argv, "ai")) {
case 'a':
{
char demo_src[256];
char demo_dst[4*sizeof(demo_src) + 1];
int i;
for (i=0; i<256; i++)
demo_src[i] = (char) i;
(void) str_quotify(demo_dst, sizeof(demo_dst),
demo_src, sizeof(demo_src));
printf("\"%.*s\"\n", sizeof(demo_dst), demo_dst);
}
break;
case 'i':
{
char demo_src[256];
char demo_dst[4*sizeof(demo_src) + 1];
size_t rv = 1;
while (rv && !(feof(stdin) || ferror(stdin))) {
rv = fread(demo_src, 1, sizeof(demo_src), stdin);
printf("\"%s\"\n", str_quotify(demo_dst, sizeof(demo_dst),
demo_src, rv));
}
}
break;
case -1:
case '?':
default:
fprintf(stderr,
"usage: %s [-a] [-i]\n"
" -a output a quotified string of all 256 chars in order\n"
" -i read from stdin, output quotified strings\n",
argv[0]);
}
}
#endif
