1 /*- 2 * Copyright (c) 2001-2014 Devin Teske <dteske@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/types.h> 31 32 #include <ctype.h> 33 #include <errno.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 38 #include "string_m.h" 39 40 /* 41 * Counts the number of occurrences of one string that appear in the source 42 * string. Return value is the total count. 43 * 44 * An example use would be if you need to know how large a block of memory 45 * needs to be for a replaceall() series. 46 */ 47 unsigned int 48 strcount(const char *source, const char *find) 49 { 50 const char *p = source; 51 size_t flen; 52 unsigned int n = 0; 53 54 /* Both parameters are required */ 55 if (source == NULL || find == NULL) 56 return (0); 57 58 /* Cache the length of find element */ 59 flen = strlen(find); 60 if (strlen(source) == 0 || flen == 0) 61 return (0); 62 63 /* Loop until the end of the string */ 64 while (*p != '\0') { 65 if (strncmp(p, find, flen) == 0) { /* found an instance */ 66 p += flen; 67 n++; 68 } else 69 p++; 70 } 71 72 return (n); 73 } 74 75 /* 76 * Replaces all occurrences of `find' in `source' with `replace'. 77 * 78 * You should not pass a string constant as the first parameter, it needs to be 79 * a pointer to an allocated block of memory. The block of memory that source 80 * points to should be large enough to hold the result. If the length of the 81 * replacement string is greater than the length of the find string, the result 82 * will be larger than the original source string. To allocate enough space for 83 * the result, use the function strcount() declared above to determine the 84 * number of occurrences and how much larger the block size needs to be. 85 * 86 * If source is not large enough, the application will crash. The return value 87 * is the length (in bytes) of the result. 88 * 89 * When an error occurs, -1 is returned and the global variable errno is set 90 * accordingly. Returns zero on success. 91 */ 92 int 93 replaceall(char *source, const char *find, const char *replace) 94 { 95 char *p; 96 char *t; 97 char *temp; 98 size_t flen; 99 size_t rlen; 100 size_t slen; 101 uint32_t n = 0; 102 103 errno = 0; /* reset global error number */ 104 105 /* Check that we have non-null parameters */ 106 if (source == NULL) 107 return (0); 108 if (find == NULL) 109 return (strlen(source)); 110 111 /* Cache the length of the strings */ 112 slen = strlen(source); 113 flen = strlen(find); 114 rlen = replace ? strlen(replace) : 0; 115 116 /* Cases where no replacements need to be made */ 117 if (slen == 0 || flen == 0 || slen < flen) 118 return (slen); 119 120 /* If replace is longer than find, we'll need to create a temp copy */ 121 if (rlen > flen) { 122 temp = malloc(slen + 1); 123 if (temp == NULL) /* could not allocate memory */ 124 return (-1); 125 memcpy(temp, source, slen + 1); 126 } else 127 temp = source; 128 129 /* Reconstruct the string with the replacements */ 130 p = source; t = temp; /* position elements */ 131 132 while (*t != '\0') { 133 if (strncmp(t, find, flen) == 0) { 134 /* found an occurrence */ 135 for (n = 0; replace && replace[n]; n++) 136 *p++ = replace[n]; 137 t += flen; 138 } else 139 *p++ = *t++; /* copy character and increment */ 140 } 141 142 /* Terminate the string */ 143 *p = '\0'; 144 145 /* Free the temporary allocated memory */ 146 if (temp != source) 147 free(temp); 148 149 /* Return the length of the completed string */ 150 return (strlen(source)); 151 } 152 153 /* 154 * Expands escape sequences in a buffer pointed to by `source'. This function 155 * steps through each character, and converts escape sequences such as "\n", 156 * "\r", "\t" and others into their respective meanings. 157 * 158 * You should not pass a string constant or literal to this function or the 159 * program will likely segmentation fault when it tries to modify the data. 160 * 161 * The string length will either shorten or stay the same depending on whether 162 * any escape sequences were converted but the amount of memory allocated does 163 * not change. 164 * 165 * Interpreted sequences are: 166 * 167 * \0NNN character with octal value NNN (0 to 3 digits) 168 * \N character with octal value N (0 thru 7) 169 * \a alert (BEL) 170 * \b backslash 171 * \f form feed 172 * \n new line 173 * \r carriage return 174 * \t horizontal tab 175 * \v vertical tab 176 * \xNN byte with hexadecimal value NN (1 to 2 digits) 177 * 178 * All other sequences are unescaped (ie. '\"' and '\#'). 179 */ 180 void strexpand(char *source) 181 { 182 uint8_t c; 183 char *chr; 184 char *pos; 185 char d[4]; 186 187 /* Initialize position elements */ 188 pos = chr = source; 189 190 /* Loop until we hit the end of the string */ 191 while (*pos != '\0') { 192 if (*chr != '\\') { 193 *pos = *chr; /* copy character to current offset */ 194 pos++; 195 chr++; 196 continue; 197 } 198 199 /* Replace the backslash with the correct character */ 200 switch (*++chr) { 201 case 'a': *pos = '\a'; break; /* bell/alert (BEL) */ 202 case 'b': *pos = '\b'; break; /* backspace */ 203 case 'f': *pos = '\f'; break; /* form feed */ 204 case 'n': *pos = '\n'; break; /* new line */ 205 case 'r': *pos = '\r'; break; /* carriage return */ 206 case 't': *pos = '\t'; break; /* horizontal tab */ 207 case 'v': *pos = '\v'; break; /* vertical tab */ 208 case 'x': /* hex value (1 to 2 digits)(\xNN) */ 209 d[2] = '\0'; /* pre-terminate the string */ 210 211 /* verify next two characters are hex */ 212 d[0] = isxdigit(*(chr+1)) ? *++chr : '\0'; 213 if (d[0] != '\0') 214 d[1] = isxdigit(*(chr+1)) ? *++chr : '\0'; 215 216 /* convert the characters to decimal */ 217 c = (uint8_t)strtoul(d, 0, 16); 218 219 /* assign the converted value */ 220 *pos = (c != 0 || d[0] == '0') ? c : *++chr; 221 break; 222 case '0': /* octal value (0 to 3 digits)(\0NNN) */ 223 d[3] = '\0'; /* pre-terminate the string */ 224 225 /* verify next three characters are octal */ 226 d[0] = (isdigit(*(chr+1)) && *(chr+1) < '8') ? 227 *++chr : '\0'; 228 if (d[0] != '\0') 229 d[1] = (isdigit(*(chr+1)) && *(chr+1) < '8') ? 230 *++chr : '\0'; 231 if (d[1] != '\0') 232 d[2] = (isdigit(*(chr+1)) && *(chr+1) < '8') ? 233 *++chr : '\0'; 234 235 /* convert the characters to decimal */ 236 c = (uint8_t)strtoul(d, 0, 8); 237 238 /* assign the converted value */ 239 *pos = c; 240 break; 241 default: /* single octal (\0..7) or unknown sequence */ 242 if (isdigit(*chr) && *chr < '8') { 243 d[0] = *chr; 244 d[1] = '\0'; 245 *pos = (uint8_t)strtoul(d, 0, 8); 246 } else 247 *pos = *chr; 248 } 249 250 /* Increment to next offset, possible next escape sequence */ 251 pos++; 252 chr++; 253 } 254 } 255 256 /* 257 * Expand only the escaped newlines in a buffer pointed to by `source'. This 258 * function steps through each character, and converts the "\n" sequence into 259 * a literal newline and the "\\n" sequence into "\n". 260 * 261 * You should not pass a string constant or literal to this function or the 262 * program will likely segmentation fault when it tries to modify the data. 263 * 264 * The string length will either shorten or stay the same depending on whether 265 * any escaped newlines were converted but the amount of memory allocated does 266 * not change. 267 */ 268 void strexpandnl(char *source) 269 { 270 uint8_t backslash = 0; 271 char *cp1; 272 char *cp2; 273 274 /* Replace '\n' with literal in dprompt */ 275 cp1 = cp2 = source; 276 while (*cp2 != '\0') { 277 *cp1 = *cp2; 278 if (*cp2 == '\\') 279 backslash++; 280 else if (*cp2 != 'n') 281 backslash = 0; 282 else if (backslash > 0) { 283 *(--cp1) = (backslash & 1) == 1 ? '\n' : 'n'; 284 backslash = 0; 285 } 286 cp1++; 287 cp2++; 288 } 289 *cp1 = *cp2; 290 } 291 292 /* 293 * Convert a string to lower case. You should not pass a string constant to 294 * this function. Only pass pointers to allocated memory with null terminated 295 * string data. 296 */ 297 void 298 strtolower(char *source) 299 { 300 char *p = source; 301 302 if (source == NULL) 303 return; 304 305 while (*p != '\0') { 306 *p = tolower(*p); 307 p++; /* would have just used `*p++' but gcc 3.x warns */ 308 } 309 } 310