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/types.h>
38 * Counts the number of occurrences of one string that appear in the source
39 * string. Return value is the total count.
41 * An example use would be if you need to know how large a block of memory
42 * needs to be for a replaceall() series.
45 strcount(const char *source, const char *find)
47 const char *p = source;
51 /* Both parameters are required */
52 if (source == NULL || find == NULL)
55 /* Cache the length of find element */
57 if (strlen(source) == 0 || flen == 0)
60 /* Loop until the end of the string */
62 if (strncmp(p, find, flen) == 0) { /* found an instance */
73 * Replaces all occurrences of `find' in `source' with `replace'.
75 * You should not pass a string constant as the first parameter, it needs to be
76 * a pointer to an allocated block of memory. The block of memory that source
77 * points to should be large enough to hold the result. If the length of the
78 * replacement string is greater than the length of the find string, the result
79 * will be larger than the original source string. To allocate enough space for
80 * the result, use the function strcount() declared above to determine the
81 * number of occurrences and how much larger the block size needs to be.
83 * If source is not large enough, the application will crash. The return value
84 * is the length (in bytes) of the result.
86 * When an error occurs, -1 is returned and the global variable errno is set
87 * accordingly. Returns zero on success.
90 replaceall(char *source, const char *find, const char *replace)
100 errno = 0; /* reset global error number */
102 /* Check that we have non-null parameters */
106 return (strlen(source));
108 /* Cache the length of the strings */
109 slen = strlen(source);
111 rlen = replace ? strlen(replace) : 0;
113 /* Cases where no replacements need to be made */
114 if (slen == 0 || flen == 0 || slen < flen)
117 /* If replace is longer than find, we'll need to create a temp copy */
119 temp = malloc(slen + 1);
120 if (temp == NULL) /* could not allocate memory */
122 memcpy(temp, source, slen + 1);
126 /* Reconstruct the string with the replacements */
127 p = source; t = temp; /* position elements */
130 if (strncmp(t, find, flen) == 0) {
131 /* found an occurrence */
132 for (n = 0; replace && replace[n]; n++)
136 *p++ = *t++; /* copy character and increment */
139 /* Terminate the string */
142 /* Free the temporary allocated memory */
146 /* Return the length of the completed string */
147 return (strlen(source));
151 * Expands escape sequences in a buffer pointed to by `source'. This function
152 * steps through each character, and converts escape sequences such as "\n",
153 * "\r", "\t" and others into their respective meanings.
155 * You should not pass a string constant or literal to this function or the
156 * program will likely segmentation fault when it tries to modify the data.
158 * The string length will either shorten or stay the same depending on whether
159 * any escape sequences were converted but the amount of memory allocated does
162 * Interpreted sequences are:
164 * \0NNN character with octal value NNN (0 to 3 digits)
165 * \N character with octal value N (0 thru 7)
173 * \xNN byte with hexadecimal value NN (1 to 2 digits)
175 * All other sequences are unescaped (ie. '\"' and '\#').
177 void strexpand(char *source)
184 /* Initialize position elements */
187 /* Loop until we hit the end of the string */
188 while (*pos != '\0') {
190 *pos = *chr; /* copy character to current offset */
196 /* Replace the backslash with the correct character */
198 case 'a': *pos = '\a'; break; /* bell/alert (BEL) */
199 case 'b': *pos = '\b'; break; /* backspace */
200 case 'f': *pos = '\f'; break; /* form feed */
201 case 'n': *pos = '\n'; break; /* new line */
202 case 'r': *pos = '\r'; break; /* carriage return */
203 case 't': *pos = '\t'; break; /* horizontal tab */
204 case 'v': *pos = '\v'; break; /* vertical tab */
205 case 'x': /* hex value (1 to 2 digits)(\xNN) */
206 d[2] = '\0'; /* pre-terminate the string */
208 /* verify next two characters are hex */
209 d[0] = isxdigit(*(chr+1)) ? *++chr : '\0';
211 d[1] = isxdigit(*(chr+1)) ? *++chr : '\0';
213 /* convert the characters to decimal */
214 c = (uint8_t)strtoul(d, 0, 16);
216 /* assign the converted value */
217 *pos = (c != 0 || d[0] == '0') ? c : *++chr;
219 case '0': /* octal value (0 to 3 digits)(\0NNN) */
220 d[3] = '\0'; /* pre-terminate the string */
222 /* verify next three characters are octal */
223 d[0] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
226 d[1] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
229 d[2] = (isdigit(*(chr+1)) && *(chr+1) < '8') ?
232 /* convert the characters to decimal */
233 c = (uint8_t)strtoul(d, 0, 8);
235 /* assign the converted value */
238 default: /* single octal (\0..7) or unknown sequence */
239 if (isdigit(*chr) && *chr < '8') {
242 *pos = (uint8_t)strtoul(d, 0, 8);
247 /* Increment to next offset, possible next escape sequence */
254 * Expand only the escaped newlines in a buffer pointed to by `source'. This
255 * function steps through each character, and converts the "\n" sequence into
256 * a literal newline and the "\\n" sequence into "\n".
258 * You should not pass a string constant or literal to this function or the
259 * program will likely segmentation fault when it tries to modify the data.
261 * The string length will either shorten or stay the same depending on whether
262 * any escaped newlines were converted but the amount of memory allocated does
265 void strexpandnl(char *source)
267 uint8_t backslash = 0;
271 /* Replace '\n' with literal in dprompt */
273 while (*cp2 != '\0') {
277 else if (*cp2 != 'n')
279 else if (backslash > 0) {
280 *(--cp1) = (backslash & 1) == 1 ? '\n' : 'n';
290 * Convert a string to lower case. You should not pass a string constant to
291 * this function. Only pass pointers to allocated memory with null terminated
295 strtolower(char *source)
304 p++; /* would have just used `*p++' but gcc 3.x warns */