wireshark/epan/strutil.c

1087 lines
24 KiB
C

/* strutil.c
* String utility routines
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* 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
* of the License, 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 "config.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <glib.h>
#include "strutil.h"
#include "emem.h"
#include <../isprint.h>
#ifdef _WIN32
#include <windows.h>
#include <tchar.h>
#include <wchar.h>
#endif
static const char hex[16] = { '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
/*
* Given a pointer into a data buffer, and to the end of the buffer,
* find the end of the (putative) line at that position in the data
* buffer.
* Return a pointer to the EOL character(s) in "*eol".
*/
const guchar *
find_line_end(const guchar *data, const guchar *dataend, const guchar **eol)
{
const guchar *lineend;
lineend = memchr(data, '\n', dataend - data);
if (lineend == NULL) {
/*
* No LF - line is probably continued in next TCP segment.
*/
lineend = dataend;
*eol = dataend;
} else {
/*
* Is the LF at the beginning of the line?
*/
if (lineend > data) {
/*
* No - is it preceded by a carriage return?
* (Perhaps it's supposed to be, but that's not guaranteed....)
*/
if (*(lineend - 1) == '\r') {
/*
* Yes. The EOL starts with the CR.
*/
*eol = lineend - 1;
} else {
/*
* No. The EOL starts with the LF.
*/
*eol = lineend;
/*
* I seem to remember that we once saw lines ending with LF-CR
* in an HTTP request or response, so check if it's *followed*
* by a carriage return.
*/
if (lineend < (dataend - 1) && *(lineend + 1) == '\r') {
/*
* It's <non-LF><LF><CR>; say it ends with the CR.
*/
lineend++;
}
}
} else {
/*
* Yes - the EOL starts with the LF.
*/
*eol = lineend;
}
/*
* Point to the character after the last character.
*/
lineend++;
}
return lineend;
}
/*
* Get the length of the next token in a line, and the beginning of the
* next token after that (if any).
* Return 0 if there is no next token.
*/
int
get_token_len(const guchar *linep, const guchar *lineend,
const guchar **next_token)
{
const guchar *tokenp;
int token_len;
tokenp = linep;
/*
* Search for a blank, a CR or an LF, or the end of the buffer.
*/
while (linep < lineend && *linep != ' ' && *linep != '\r' && *linep != '\n')
linep++;
token_len = (int) (linep - tokenp);
/*
* Skip trailing blanks.
*/
while (linep < lineend && *linep == ' ')
linep++;
*next_token = linep;
return token_len;
}
#define INITIAL_FMTBUF_SIZE 128
/*
* Given a string, generate a string from it that shows non-printable
* characters as C-style escapes, and return a pointer to it.
*/
gchar *
format_text(const guchar *string, size_t len)
{
static gchar *fmtbuf[3];
static int fmtbuf_len[3];
static int idx;
int column;
const guchar *stringend = string + len;
guchar c;
int i;
idx = (idx + 1) % 3;
/*
* Allocate the buffer if it's not already allocated.
*/
if (fmtbuf[idx] == NULL) {
fmtbuf[idx] = g_malloc(INITIAL_FMTBUF_SIZE);
fmtbuf_len[idx] = INITIAL_FMTBUF_SIZE;
}
column = 0;
while (string < stringend) {
/*
* Is there enough room for this character, if it expands to
* a backslash plus 3 octal digits (which is the most it can
* expand to), and also enough room for a terminating '\0'?
*/
if (column+3+1 >= fmtbuf_len[idx]) {
/*
* Double the buffer's size if it's not big enough.
* The size of the buffer starts at 128, so doubling its size
* adds at least another 128 bytes, which is more than enough
* for one more character plus a terminating '\0'.
*/
fmtbuf_len[idx] = fmtbuf_len[idx] * 2;
fmtbuf[idx] = g_realloc(fmtbuf[idx], fmtbuf_len[idx]);
}
c = *string++;
if (isprint(c)) {
fmtbuf[idx][column] = c;
column++;
} else {
fmtbuf[idx][column] = '\\';
column++;
switch (c) {
case '\a':
fmtbuf[idx][column] = 'a';
column++;
break;
case '\b':
fmtbuf[idx][column] = 'b'; /* BS */
column++;
break;
case '\f':
fmtbuf[idx][column] = 'f'; /* FF */
column++;
break;
case '\n':
fmtbuf[idx][column] = 'n'; /* NL */
column++;
break;
case '\r':
fmtbuf[idx][column] = 'r'; /* CR */
column++;
break;
case '\t':
fmtbuf[idx][column] = 't'; /* tab */
column++;
break;
case '\v':
fmtbuf[idx][column] = 'v';
column++;
break;
default:
i = (c>>6)&03;
fmtbuf[idx][column] = i + '0';
column++;
i = (c>>3)&07;
fmtbuf[idx][column] = i + '0';
column++;
i = (c>>0)&07;
fmtbuf[idx][column] = i + '0';
column++;
break;
}
}
}
fmtbuf[idx][column] = '\0';
return fmtbuf[idx];
}
/*
* Given a string, generate a string from it that shows non-printable
* characters as C-style escapes except a whitespace character
* (space, tab, carriage return, new line, vertical tab, or formfeed)
* which will be replaced by a space, and return a pointer to it.
*/
gchar *
format_text_wsp(const guchar *string, size_t len)
{
static gchar *fmtbuf[3];
static int fmtbuf_len[3];
static int idx;
int column;
const guchar *stringend = string + len;
guchar c;
int i;
idx = (idx + 1) % 3;
/*
* Allocate the buffer if it's not already allocated.
*/
if (fmtbuf[idx] == NULL) {
fmtbuf[idx] = g_malloc(INITIAL_FMTBUF_SIZE);
fmtbuf_len[idx] = INITIAL_FMTBUF_SIZE;
}
column = 0;
while (string < stringend) {
/*
* Is there enough room for this character, if it expands to
* a backslash plus 3 octal digits (which is the most it can
* expand to), and also enough room for a terminating '\0'?
*/
if (column+3+1 >= fmtbuf_len[idx]) {
/*
* Double the buffer's size if it's not big enough.
* The size of the buffer starts at 128, so doubling its size
* adds at least another 128 bytes, which is more than enough
* for one more character plus a terminating '\0'.
*/
fmtbuf_len[idx] = fmtbuf_len[idx] * 2;
fmtbuf[idx] = g_realloc(fmtbuf[idx], fmtbuf_len[idx]);
}
c = *string++;
if (isprint(c)) {
fmtbuf[idx][column] = c;
column++;
} else if (isspace(c)) {
fmtbuf[idx][column] = ' ';
column++;
} else {
fmtbuf[idx][column] = '\\';
column++;
switch (c) {
case '\a':
fmtbuf[idx][column] = 'a';
column++;
break;
case '\b':
fmtbuf[idx][column] = 'b'; /* BS */
column++;
break;
case '\f':
fmtbuf[idx][column] = 'f'; /* FF */
column++;
break;
case '\n':
fmtbuf[idx][column] = 'n'; /* NL */
column++;
break;
case '\r':
fmtbuf[idx][column] = 'r'; /* CR */
column++;
break;
case '\t':
fmtbuf[idx][column] = 't'; /* tab */
column++;
break;
case '\v':
fmtbuf[idx][column] = 'v';
column++;
break;
default:
i = (c>>6)&03;
fmtbuf[idx][column] = i + '0';
column++;
i = (c>>3)&07;
fmtbuf[idx][column] = i + '0';
column++;
i = (c>>0)&07;
fmtbuf[idx][column] = i + '0';
column++;
break;
}
}
}
fmtbuf[idx][column] = '\0';
return fmtbuf[idx];
}
static gboolean
is_byte_sep(guint8 c)
{
return (c == '-' || c == ':' || c == '.');
}
/* Turn a string of hex digits with optional separators (defined by
* is_byte_sep() into a byte array.
*/
gboolean
hex_str_to_bytes(const char *hex_str, GByteArray *bytes, gboolean force_separators) {
guint8 val;
const guchar *p, *q, *r, *s, *punct;
char four_digits_first_half[3];
char four_digits_second_half[3];
char two_digits[3];
char one_digit[2];
if (! hex_str || ! bytes) {
return FALSE;
}
g_byte_array_set_size(bytes, 0);
p = (const guchar *)hex_str;
while (*p) {
q = p+1;
r = p+2;
s = p+3;
if (*q && *r && *s
&& isxdigit(*p) && isxdigit(*q) &&
isxdigit(*r) && isxdigit(*s)) {
four_digits_first_half[0] = *p;
four_digits_first_half[1] = *q;
four_digits_first_half[2] = '\0';
four_digits_second_half[0] = *r;
four_digits_second_half[1] = *s;
four_digits_second_half[2] = '\0';
/*
* Four or more hex digits in a row.
*/
val = (guint8) strtoul(four_digits_first_half, NULL, 16);
g_byte_array_append(bytes, &val, 1);
val = (guint8) strtoul(four_digits_second_half, NULL, 16);
g_byte_array_append(bytes, &val, 1);
punct = s + 1;
if (*punct) {
/*
* Make sure the character after
* the forth hex digit is a byte
* separator, i.e. that we don't have
* more than four hex digits, or a
* bogus character.
*/
if (is_byte_sep(*punct)) {
p = punct + 1;
continue;
}
else if (force_separators) {
return FALSE;
}
}
p = punct;
continue;
}
else if (*q && isxdigit(*p) && isxdigit(*q)) {
two_digits[0] = *p;
two_digits[1] = *q;
two_digits[2] = '\0';
/*
* Two hex digits in a row.
*/
val = (guint8) strtoul(two_digits, NULL, 16);
g_byte_array_append(bytes, &val, 1);
punct = q + 1;
if (*punct) {
/*
* Make sure the character after
* the second hex digit is a byte
* separator, i.e. that we don't have
* more than two hex digits, or a
* bogus character.
*/
if (is_byte_sep(*punct)) {
p = punct + 1;
continue;
}
else if (force_separators) {
return FALSE;
}
}
p = punct;
continue;
}
else if (*q && isxdigit(*p) && is_byte_sep(*q)) {
one_digit[0] = *p;
one_digit[1] = '\0';
/*
* Only one hex digit (not at the end of the string)
*/
val = (guint8) strtoul(one_digit, NULL, 16);
g_byte_array_append(bytes, &val, 1);
p = q + 1;
continue;
}
else if (!*q && isxdigit(*p)) {
one_digit[0] = *p;
one_digit[1] = '\0';
/*
* Only one hex digit (at the end of the string)
*/
val = (guint8) strtoul(one_digit, NULL, 16);
g_byte_array_append(bytes, &val, 1);
p = q;
continue;
}
else {
return FALSE;
}
}
return TRUE;
}
/*
* Turn an RFC 3986 percent-encoded string into a byte array.
* XXX - We don't check for reserved characters.
*/
#define HEX_DIGIT_BUF_LEN 3
gboolean
uri_str_to_bytes(const char *uri_str, GByteArray *bytes) {
guint8 val;
const guchar *p;
guchar hex_digit[HEX_DIGIT_BUF_LEN];
g_byte_array_set_size(bytes, 0);
if (! uri_str) {
return FALSE;
}
p = (const guchar *)uri_str;
while (*p) {
if (! isascii(*p) || ! isprint(*p))
return FALSE;
if (*p == '%') {
p++;
if (*p == '\0') return FALSE;
hex_digit[0] = *p;
p++;
if (*p == '\0') return FALSE;
hex_digit[1] = *p;
hex_digit[2] = '\0';
if (! isxdigit(hex_digit[0]) || ! isxdigit(hex_digit[1]))
return FALSE;
val = (guint8) strtoul((char *)hex_digit, NULL, 16);
g_byte_array_append(bytes, &val, 1);
} else {
g_byte_array_append(bytes, (const guint8 *) p, 1);
}
p++;
}
return TRUE;
}
/*
* Given a GByteArray, generate a string from it that shows non-printable
* characters as percent-style escapes, and return a pointer to it.
*/
gchar *
format_uri(const GByteArray *bytes, const gchar *reserved_chars)
{
static gchar *fmtbuf[3];
static guint fmtbuf_len[3];
static guint idx;
const guchar *reserved_def = ":/?#[]@!$&'()*+,;= ";
const guchar *reserved = reserved_def;
guint8 c;
guint column, i;
gboolean is_reserved = FALSE;
if (! bytes)
return "";
idx = (idx + 1) % 3;
if (reserved_chars)
reserved = reserved_chars;
/*
* Allocate the buffer if it's not already allocated.
*/
if (fmtbuf[idx] == NULL) {
fmtbuf[idx] = g_malloc(INITIAL_FMTBUF_SIZE);
fmtbuf_len[idx] = INITIAL_FMTBUF_SIZE;
}
for (column = 0; column < bytes->len; column++) {
/*
* Is there enough room for this character, if it expands to
* a percent plus 2 hex digits (which is the most it can
* expand to), and also enough room for a terminating '\0'?
*/
if (column+2+1 >= fmtbuf_len[idx]) {
/*
* Double the buffer's size if it's not big enough.
* The size of the buffer starts at 128, so doubling its size
* adds at least another 128 bytes, which is more than enough
* for one more character plus a terminating '\0'.
*/
fmtbuf_len[idx] = fmtbuf_len[idx] * 2;
fmtbuf[idx] = g_realloc(fmtbuf[idx], fmtbuf_len[idx]);
}
c = bytes->data[column];
if (!isascii(c) || !isprint(c) || c == '%') {
is_reserved = TRUE;
}
for (i = 0; reserved[i]; i++) {
if (c == reserved[i])
is_reserved = TRUE;
}
if (!is_reserved) {
fmtbuf[idx][column] = c;
} else {
fmtbuf[idx][column] = '%';
column++;
fmtbuf[idx][column] = hex[c >> 4];
column++;
fmtbuf[idx][column] = hex[c & 0xF];
}
}
fmtbuf[idx][column] = '\0';
return fmtbuf[idx];
}
/**
* Create a copy of a GByteArray
*
* @param ba The byte array to be copied.
* @return If ba exists, a freshly allocated copy. NULL otherwise.
*
*/
GByteArray *
byte_array_dup(GByteArray *ba) {
GByteArray *new_ba;
if (!ba)
return NULL;
new_ba = g_byte_array_new();
g_byte_array_append(new_ba, ba->data, ba->len);
return new_ba;
}
#define SUBID_BUF_LEN 5
gboolean
oid_str_to_bytes(const char *oid_str, GByteArray *bytes) {
guint32 subid0, subid, sicnt, i;
const char *p, *dot;
guint8 buf[SUBID_BUF_LEN];
g_byte_array_set_size(bytes, 0);
/* check syntax */
p = oid_str;
dot = NULL;
while (*p) {
if (!isdigit((guchar)*p) && (*p != '.')) return FALSE;
if (*p == '.') {
if (p == oid_str) return FALSE;
if (!*(p+1)) return FALSE;
if ((p-1) == dot) return FALSE;
dot = p;
}
p++;
}
if (!dot) return FALSE;
p = oid_str;
sicnt = 0;
subid0 = 0; /* squelch GCC complaints */
while (*p) {
subid = 0;
while (isdigit((guchar)*p)) {
subid *= 10;
subid += *p - '0';
p++;
}
if (sicnt == 0) {
subid0 = subid;
if (subid0 > 2) return FALSE;
} else if (sicnt == 1) {
if ((subid0 < 2) && (subid > 39)) return FALSE;
subid += 40 * subid0;
}
if (sicnt) {
i = SUBID_BUF_LEN;
do {
i--;
buf[i] = 0x80 | (subid % 0x80);
subid >>= 7;
} while (subid && i);
buf[SUBID_BUF_LEN-1] &= 0x7F;
g_byte_array_append(bytes, buf + i, SUBID_BUF_LEN - i);
}
sicnt++;
if (*p) p++;
}
return TRUE;
}
/**
* Compare the contents of two GByteArrays
*
* @param ba1 A byte array
* @param ba2 A byte array
* @return If both arrays are non-NULL and their lengths are equal and
* their contents are equal, returns TRUE. Otherwise, returns
* FALSE.
*
* XXX - Should this be in strutil.c?
*/
gboolean
byte_array_equal(GByteArray *ba1, GByteArray *ba2) {
if (!ba1 || !ba2)
return FALSE;
if (ba1->len != ba2->len)
return FALSE;
if (memcmp(ba1->data, ba2->data, ba1->len) != 0)
return FALSE;
return TRUE;
}
/* Return a XML escaped representation of the unescaped string.
* The returned string must be freed when no longer in use. */
gchar *
xml_escape(const gchar *unescaped)
{
GString *buffer = g_string_sized_new(128);
const gchar *p;
gchar c;
p = unescaped;
while ( (c = *p++) ) {
switch (c) {
case '<':
g_string_append(buffer, "&lt;");
break;
case '>':
g_string_append(buffer, "&gt;");
break;
case '&':
g_string_append(buffer, "&amp;");
break;
case '\'':
g_string_append(buffer, "&apos;");
break;
case '"':
g_string_append(buffer, "&quot;");
break;
default:
g_string_append_c(buffer, c);
break;
}
}
/* Return the string value contained within the GString
* after getting rid of the GString structure.
* This is the way to do this, see the GLib reference. */
return g_string_free(buffer, FALSE);
}
/* Return the first occurrence of needle in haystack.
* If not found, return NULL.
* If either haystack or needle has 0 length, return NULL.
* Algorithm copied from GNU's glibc 2.3.2 memcmp() */
const guint8 *
epan_memmem(const guint8 *haystack, guint haystack_len,
const guint8 *needle, guint needle_len)
{
const guint8 *begin;
const guint8 *const last_possible
= haystack + haystack_len - needle_len;
if (needle_len == 0) {
return NULL;
}
if (needle_len > haystack_len) {
return NULL;
}
for (begin = haystack ; begin <= last_possible; ++begin) {
if (begin[0] == needle[0] &&
!memcmp(&begin[1], needle + 1,
needle_len - 1)) {
return begin;
}
}
return NULL;
}
/*
* Scan the search string to make sure it's valid hex. Return the
* number of bytes in nbytes.
*/
guint8 *
convert_string_to_hex(const char *string, size_t *nbytes)
{
size_t n_bytes;
const char *p;
guchar c;
guint8 *bytes, *q, byte_val;
n_bytes = 0;
p = &string[0];
for (;;) {
c = *p++;
if (c == '\0')
break;
if (isspace(c))
continue; /* allow white space */
if (c==':' || c=='.' || c=='-')
continue; /* skip any ':', '.', or '-' between bytes */
if (!isxdigit(c)) {
/* Not a valid hex digit - fail */
return NULL;
}
/*
* We can only match bytes, not nibbles; we must have a valid
* hex digit immediately after that hex digit.
*/
c = *p++;
if (!isxdigit(c))
return NULL;
/* 2 hex digits = 1 byte */
n_bytes++;
}
/*
* Were we given any hex digits?
*/
if (n_bytes == 0) {
/* No. */
return NULL;
}
/*
* OK, it's valid, and it generates "n_bytes" bytes; generate the
* raw byte array.
*/
bytes = g_malloc(n_bytes);
p = &string[0];
q = &bytes[0];
for (;;) {
c = *p++;
if (c == '\0')
break;
if (isspace(c))
continue; /* allow white space */
if (c==':' || c=='.' || c=='-')
continue; /* skip any ':', '.', or '-' between bytes */
/* From the loop above, we know this is a hex digit */
if (isdigit(c))
byte_val = c - '0';
else if (c >= 'a')
byte_val = (c - 'a') + 10;
else
byte_val = (c - 'A') + 10;
byte_val <<= 4;
/* We also know this is a hex digit */
c = *p++;
if (isdigit(c))
byte_val |= c - '0';
else if (c >= 'a')
byte_val |= (c - 'a') + 10;
else if (c >= 'A')
byte_val |= (c - 'A') + 10;
*q++ = byte_val;
}
*nbytes = n_bytes;
return bytes;
}
/*
* Copy if if it's a case-sensitive search; uppercase it if it's
* a case-insensitive search.
*/
char *
convert_string_case(const char *string, gboolean case_insensitive)
{
if (case_insensitive) {
return g_utf8_strup(string, -1);
} else {
return g_strdup(string);
}
}
char *
epan_strcasestr(const char *haystack, const char *needle)
{
gsize hlen = strlen(haystack);
gsize nlen = strlen(needle);
while (hlen-- >= nlen) {
if (!g_ascii_strncasecmp(haystack, needle, nlen))
return (char*) haystack;
haystack++;
}
return NULL;
}
const char *
string_or_null(const char *string)
{
if (string)
return string;
return "[NULL]";
}
int
escape_string_len(const char *string)
{
const char *p;
gchar c;
int repr_len;
repr_len = 0;
for (p = string; (c = *p) != '\0'; p++) {
/* Backslashes and double-quotes must
* be escaped */
if (c == '\\' || c == '"') {
repr_len += 2;
}
/* Values that can't nicely be represented
* in ASCII need to be escaped. */
else if (!isprint((unsigned char)c)) {
/* c --> \xNN */
repr_len += 4;
}
/* Other characters are just passed through. */
else {
repr_len++;
}
}
return repr_len + 2; /* string plus leading and trailing quotes */
}
char *
escape_string(char *buf, const char *string)
{
const gchar *p;
gchar c;
char *bufp;
char hexbuf[3];
bufp = buf;
*bufp++ = '"';
for (p = string; (c = *p) != '\0'; p++) {
/* Backslashes and double-quotes must
* be escaped. */
if (c == '\\' || c == '"') {
*bufp++ = '\\';
*bufp++ = c;
}
/* Values that can't nicely be represented
* in ASCII need to be escaped. */
else if (!isprint((unsigned char)c)) {
/* c --> \xNN */
g_snprintf(hexbuf,sizeof(hexbuf), "%02x", (unsigned char) c);
*bufp++ = '\\';
*bufp++ = 'x';
*bufp++ = hexbuf[0];
*bufp++ = hexbuf[1];
}
/* Other characters are just passed through. */
else {
*bufp++ = c;
}
}
*bufp++ = '"';
*bufp = '\0';
return buf;
}
#define GN_CHAR_ALPHABET_SIZE 128
static gunichar IA5_default_alphabet[GN_CHAR_ALPHABET_SIZE] = {
/*ITU-T recommendation T.50 specifies International Reference Alphabet 5 (IA5) */
'?', '?', '?', '?', '?', '?', '?', '?',
'?', '?', '?', '?', '?', '?', '?', '?',
'?', '?', '?', '?', '?', '?', '?', '?',
'?', '?', '?', '?', '?', '?', '?', '?',
' ', '!', '\"','#', '$', '%', '&', '\'',
'(', ')', '*', '+', ',', '-', '.', '/',
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', ':', ';', '<', '=', '>', '?',
'@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
'X', 'Y', 'Z', '[', '\\', ']', '^', '_',
'`', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', '{', '|', '}', '~', '?'
};
static gunichar
char_def_ia5_alphabet_decode(unsigned char value)
{
if (value < GN_CHAR_ALPHABET_SIZE)
{
return IA5_default_alphabet[value];
}
else
{
return '?';
}
}
void
IA5_7BIT_decode(unsigned char * dest, const unsigned char* src, int len)
{
int i, j;
gunichar buf;
for (i = 0, j = 0; j < len; j++)
{
buf = char_def_ia5_alphabet_decode(src[j]);
i += g_unichar_to_utf8(buf,&(dest[i]));
}
dest[i]=0;
return;
}
/*
* This function takes a string and copies it, inserting a 'chr' before
* every 'chr' in it.
*/
gchar*
ws_strdup_escape_char (const gchar *str, const gchar chr)
{
const gchar *p;
gchar *q, *new_str;
if(!str)
return NULL;
p = str;
/* Worst case: A string that is full of 'chr' */
q = new_str = g_malloc (strlen(str) * 2 + 1);
while(*p != 0)
{
if(*p == chr)
*q++ = chr;
*q++ = *p++;
}
*q = '\0';
return new_str;
}
/*
* This function takes a string and copies it, removing any occurences of double
* 'chr' with a single 'chr'.
*/
gchar*
ws_strdup_unescape_char (const gchar *str, const char chr)
{
const gchar *p;
gchar *q, *new_str;
if(!str)
return NULL;
p = str;
/* Worst case: A string that contains no 'chr' */
q = new_str = g_malloc (strlen(str) + 1);
while(*p != 0)
{
*q++ = *p;
if ((*p == chr) && (*(p+1) == chr))
p += 2;
else
p++;
}
*q = '\0';
return new_str;
}
/* Create a newly-allocated string with replacement values. */
gchar *string_replace(const gchar* str, const gchar *old_val, const gchar *new_val) {
gchar **str_parts;
gchar *new_str;
if (!str || !old_val) {
return NULL;
}
str_parts = g_strsplit(str, old_val, 0);
new_str = g_strjoinv(new_val, str_parts);
g_strfreev(str_parts);
return new_str;
}