2 * Copyright (c) 2001-2014 Devin Teske <dteske@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 #include <sys/types.h>
39 * Counts the number of occurrences of one string that appear in the source
40 * string. Return value is the total count.
42 * An example use would be if you need to know how large a block of memory
43 * needs to be for a replaceall() series.
46 strcount(const char *source, const char *find)
48 const char *p = source;
52 /* Both parameters are required */
53 if (source == NULL || find == NULL)
56 /* Cache the length of find element */
58 if (strlen(source) == 0 || flen == 0)
61 /* Loop until the end of the string */
63 if (strncmp(p, find, flen) == 0) { /* found an instance */
74 * Replaces all occurrences of `find' in `source' with `replace'.
76 * You should not pass a string constant as the first parameter, it needs to be
77 * a pointer to an allocated block of memory. The block of memory that source
78 * points to should be large enough to hold the result. If the length of the
79 * replacement string is greater than the length of the find string, the result
80 * will be larger than the original source string. To allocate enough space for
81 * the result, use the function strcount() declared above to determine the
82 * number of occurrences and how much larger the block size needs to be.
84 * If source is not large enough, the application will crash. The return value
85 * is the length (in bytes) of the result.
87 * When an error occurs, -1 is returned and the global variable errno is set
88 * accordingly. Returns zero on success.
91 replaceall(char *source, const char *find, const char *replace)
101 errno = 0; /* reset global error number */
103 /* Check that we have non-null parameters */
107 return (strlen(source));
109 /* Cache the length of the strings */
110 slen = strlen(source);
112 rlen = replace ? strlen(replace) : 0;
114 /* Cases where no replacements need to be made */
115 if (slen == 0 || flen == 0 || slen < flen)
118 /* If replace is longer than find, we'll need to create a temp copy */
120 temp = malloc(slen + 1);
121 if (temp == NULL) /* could not allocate memory */
123 memcpy(temp, source, slen + 1);
127 /* Reconstruct the string with the replacements */
128 p = source; t = temp; /* position elements */
131 if (strncmp(t, find, flen) == 0) {
132 /* found an occurrence */
133 for (n = 0; replace && replace[n]; n++)
137 *p++ = *t++; /* copy character and increment */
140 /* Terminate the string */
143 /* Free the temporary allocated memory */
147 /* Return the length of the completed string */
148 return (strlen(source));
152 * Expands escape sequences in a buffer pointed to by `source'. This function
153 * steps through each character, and converts escape sequences such as "\n",
154 * "\r", "\t" and others into their respective meanings.
156 * You should not pass a string constant or literal to this function or the
157 * program will likely segmentation fault when it tries to modify the data.
159 * The string length will either shorten or stay the same depending on whether
160 * any escape sequences were converted but the amount of memory allocated does
163 * Interpreted sequences are:
165 * \0NNN character with octal value NNN (0 to 3 digits)
166 * \N character with octal value N (0 thru 7)
174 * \xNN byte with hexadecimal value NN (1 to 2 digits)
176 * All other sequences are unescaped (ie. '\"' and '\#').
178 void strexpand(char *source)
185 /* Initialize position elements */
188 /* Loop until we hit the end of the string */
189 while (*pos != '\0') {
191 *pos = *chr; /* copy character to current offset */
197 /* Replace the backslash with the correct character */
199 case 'a': *pos = '\a'; break; /* bell/alert (BEL) */
200 case 'b': *pos = '\b'; break; /* backspace */
201 case 'f': *pos = '\f'; break; /* form feed */
202 case 'n': *pos = '\n'; break; /* new line */
203 case 'r': *pos = '\r'; break; /* carriage return */
204 case 't': *pos = '\t'; break; /* horizontal tab */
205 case 'v': *pos = '\v'; break; /* vertical tab */
206 case 'x': /* hex value (1 to 2 digits)(\xNN) */
207 d[2] = '\0'; /* pre-terminate the string */
209 /* verify next two characters are hex */
210 d[0] = isxdigit(*(chr+1)) ? *++chr : '\0';
212 d[1] = isxdigit(*(chr+1)) ? *++chr : '\0';
214 /* convert the characters to decimal */
215 c = (uint8_t)strtoul(d, 0, 16);
217 /* assign the converted value */
218 *pos = (c != 0 || d[0] == '0') ? c : *++chr;
220 case '0': /* octal value (0 to 3 digits)(\0NNN) */
221 d[3] = '\0'; /* pre-terminate the string */
223 /* verify next three characters are octal */
224 d[0] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
227 d[1] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
230 d[2] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
233 /* convert the characters to decimal */
234 c = (uint8_t)strtoul(d, 0, 8);
236 /* assign the converted value */
239 default: /* single octal (\0..7) or unknown sequence */
240 if (isdigit(*chr) && *chr < '8') {
243 *pos = (uint8_t)strtoul(d, 0, 8);
248 /* Increment to next offset, possible next escape sequence */
255 * Expand only the escaped newlines in a buffer pointed to by `source'. This
256 * function steps through each character, and converts the "\n" sequence into
257 * a literal newline and the "\\n" sequence into "\n".
259 * You should not pass a string constant or literal to this function or the
260 * program will likely segmentation fault when it tries to modify the data.
262 * The string length will either shorten or stay the same depending on whether
263 * any escaped newlines were converted but the amount of memory allocated does
266 void strexpandnl(char *source)
268 uint8_t backslash = 0;
272 /* Replace '\n' with literal in dprompt */
274 while (*cp2 != '\0') {
278 else if (*cp2 != 'n')
280 else if (backslash > 0) {
281 *(--cp1) = (backslash & 1) == 1 ? '\n' : 'n';
291 * Convert a string to lower case. You should not pass a string constant to
292 * this function. Only pass pointers to allocated memory with null terminated
296 strtolower(char *source)
305 p++; /* would have just used `*p++' but gcc 3.x warns */