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/*-
* Copyright (c) 2001-2014 Devin Teske <dteske@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "string_m.h"
/*
* Counts the number of occurrences of one string that appear in the source
* string. Return value is the total count.
*
* An example use would be if you need to know how large a block of memory
* needs to be for a replaceall() series.
*/
unsigned int
strcount(const char *source, const char *find)
{
const char *p = source;
size_t flen;
unsigned int n = 0;
/* Both parameters are required */
if (source == NULL || find == NULL)
return (0);
/* Cache the length of find element */
flen = strlen(find);
if (strlen(source) == 0 || flen == 0)
return (0);
/* Loop until the end of the string */
while (*p != '\0') {
if (strncmp(p, find, flen) == 0) { /* found an instance */
p += flen;
n++;
} else
p++;
}
return (n);
}
/*
* Replaces all occurrences of `find' in `source' with `replace'.
*
* You should not pass a string constant as the first parameter, it needs to be
* a pointer to an allocated block of memory. The block of memory that source
* points to should be large enough to hold the result. If the length of the
* replacement string is greater than the length of the find string, the result
* will be larger than the original source string. To allocate enough space for
* the result, use the function strcount() declared above to determine the
* number of occurrences and how much larger the block size needs to be.
*
* If source is not large enough, the application will crash. The return value
* is the length (in bytes) of the result.
*
* When an error occurs, -1 is returned and the global variable errno is set
* accordingly. Returns zero on success.
*/
int
replaceall(char *source, const char *find, const char *replace)
{
char *p;
char *t;
char *temp;
size_t flen;
size_t rlen;
size_t slen;
uint32_t n = 0;
errno = 0; /* reset global error number */
/* Check that we have non-null parameters */
if (source == NULL)
return (0);
if (find == NULL)
return (strlen(source));
/* Cache the length of the strings */
slen = strlen(source);
flen = strlen(find);
rlen = replace ? strlen(replace) : 0;
/* Cases where no replacements need to be made */
if (slen == 0 || flen == 0 || slen < flen)
return (slen);
/* If replace is longer than find, we'll need to create a temp copy */
if (rlen > flen) {
temp = malloc(slen + 1);
if (errno != 0) /* could not allocate memory */
return (-1);
strcpy(temp, source);
} else
temp = source;
/* Reconstruct the string with the replacements */
p = source; t = temp; /* position elements */
while (*t != '\0') {
if (strncmp(t, find, flen) == 0) {
/* found an occurrence */
for (n = 0; replace && replace[n]; n++)
*p++ = replace[n];
t += flen;
} else
*p++ = *t++; /* copy character and increment */
}
/* Terminate the string */
*p = '\0';
/* Free the temporary allocated memory */
if (temp != source)
free(temp);
/* Return the length of the completed string */
return (strlen(source));
}
/*
* Expands escape sequences in a buffer pointed to by `source'. This function
* steps through each character, and converts escape sequences such as "\n",
* "\r", "\t" and others into their respective meanings.
*
* You should not pass a string constant or literal to this function or the
* program will likely segmentation fault when it tries to modify the data.
*
* The string length will either shorten or stay the same depending on whether
* any escape sequences were converted but the amount of memory allocated does
* not change.
*
* Interpreted sequences are:
*
* \0NNN character with octal value NNN (0 to 3 digits)
* \N character with octal value N (0 thru 7)
* \a alert (BEL)
* \b backslash
* \f form feed
* \n new line
* \r carriage return
* \t horizontal tab
* \v vertical tab
* \xNN byte with hexadecimal value NN (1 to 2 digits)
*
* All other sequences are unescaped (ie. '\"' and '\#').
*/
void strexpand(char *source)
{
uint8_t c;
char *chr;
char *pos;
char d[4];
/* Initialize position elements */
pos = chr = source;
/* Loop until we hit the end of the string */
while (*pos != '\0') {
if (*chr != '\\') {
*pos = *chr; /* copy character to current offset */
pos++;
chr++;
continue;
}
/* Replace the backslash with the correct character */
switch (*++chr) {
case 'a': *pos = '\a'; break; /* bell/alert (BEL) */
case 'b': *pos = '\b'; break; /* backspace */
case 'f': *pos = '\f'; break; /* form feed */
case 'n': *pos = '\n'; break; /* new line */
case 'r': *pos = '\r'; break; /* carriage return */
case 't': *pos = '\t'; break; /* horizontal tab */
case 'v': *pos = '\v'; break; /* vertical tab */
case 'x': /* hex value (1 to 2 digits)(\xNN) */
d[2] = '\0'; /* pre-terminate the string */
/* verify next two characters are hex */
d[0] = isxdigit(*(chr+1)) ? *++chr : '\0';
if (d[0] != '\0')
d[1] = isxdigit(*(chr+1)) ? *++chr : '\0';
/* convert the characters to decimal */
c = (uint8_t)strtoul(d, 0, 16);
/* assign the converted value */
*pos = (c != 0 || d[0] == '0') ? c : *++chr;
break;
case '0': /* octal value (0 to 3 digits)(\0NNN) */
d[3] = '\0'; /* pre-terminate the string */
/* verify next three characters are octal */
d[0] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
*++chr : '\0';
if (d[0] != '\0')
d[1] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
*++chr : '\0';
if (d[1] != '\0')
d[2] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
*++chr : '\0';
/* convert the characters to decimal */
c = (uint8_t)strtoul(d, 0, 8);
/* assign the converted value */
*pos = c;
break;
default: /* single octal (\0..7) or unknown sequence */
if (isdigit(*chr) && *chr < '8') {
d[0] = *chr;
d[1] = '\0';
*pos = (uint8_t)strtoul(d, 0, 8);
} else
*pos = *chr;
}
/* Increment to next offset, possible next escape sequence */
pos++;
chr++;
}
}
/*
* Expand only the escaped newlines in a buffer pointed to by `source'. This
* function steps through each character, and converts the "\n" sequence into
* a literal newline and the "\\n" sequence into "\n".
*
* You should not pass a string constant or literal to this function or the
* program will likely segmentation fault when it tries to modify the data.
*
* The string length will either shorten or stay the same depending on whether
* any escaped newlines were converted but the amount of memory allocated does
* not change.
*/
void strexpandnl(char *source)
{
uint8_t backslash = 0;
char *cp1;
char *cp2;
/* Replace '\n' with literal in dprompt */
cp1 = cp2 = source;
while (*cp2 != '\0') {
*cp1 = *cp2;
if (*cp2 == '\\')
backslash++;
else if (*cp2 != 'n')
backslash = 0;
else if (backslash > 0) {
*(--cp1) = (backslash & 1) == 1 ? '\n' : 'n';
backslash = 0;
}
cp1++;
cp2++;
}
*cp1 = *cp2;
}
/*
* Convert a string to lower case. You should not pass a string constant to
* this function. Only pass pointers to allocated memory with null terminated
* string data.
*/
void
strtolower(char *source)
{
char *p = source;
if (source == NULL)
return;
while (*p != '\0') {
*p = tolower(*p);
p++; /* would have just used `*p++' but gcc 3.x warns */
}
}