strnsubst.c revision 1.1.10.2
1 1.1.10.2 bouyer /* $xMach: strnsubst.c,v 1.3 2002/02/23 02:10:24 jmallett Exp $ */ 2 1.1.10.2 bouyer 3 1.1.10.2 bouyer /* 4 1.1.10.2 bouyer * Copyright (c) 2002 J. Mallett. All rights reserved. 5 1.1.10.2 bouyer * You may do whatever you want with this file as long as 6 1.1.10.2 bouyer * the above copyright and this notice remain intact, along 7 1.1.10.2 bouyer * with the following statement: 8 1.1.10.2 bouyer * For the man who taught me vi, and who got too old, too young. 9 1.1.10.2 bouyer */ 10 1.1.10.2 bouyer 11 1.1.10.2 bouyer #include <sys/cdefs.h> 12 1.1.10.2 bouyer #ifndef lint 13 1.1.10.2 bouyer #if 0 14 1.1.10.2 bouyer __FBSDID("$FreeBSD: src/usr.bin/xargs/strnsubst.c,v 1.8 2005/12/30 23:22:50 jmallett Exp $"); 15 1.1.10.2 bouyer #endif 16 1.1.10.2 bouyer __RCSID("$NetBSD: strnsubst.c,v 1.1.10.2 2008/01/21 21:17:55 bouyer Exp $"); 17 1.1.10.2 bouyer #endif /* not lint */ 18 1.1.10.2 bouyer 19 1.1.10.2 bouyer #include <err.h> 20 1.1.10.2 bouyer #include <stdlib.h> 21 1.1.10.2 bouyer #include <string.h> 22 1.1.10.2 bouyer #include <unistd.h> 23 1.1.10.2 bouyer #include <stdint.h> 24 1.1.10.2 bouyer 25 1.1.10.2 bouyer void strnsubst(char **, const char *, const char *, size_t); 26 1.1.10.2 bouyer 27 1.1.10.2 bouyer /* 28 1.1.10.2 bouyer * Replaces str with a string consisting of str with match replaced with 29 1.1.10.2 bouyer * replstr as many times as can be done before the constructed string is 30 1.1.10.2 bouyer * maxsize bytes large. It does not free the string pointed to by str, it 31 1.1.10.2 bouyer * is up to the calling program to be sure that the original contents of 32 1.1.10.2 bouyer * str as well as the new contents are handled in an appropriate manner. 33 1.1.10.2 bouyer * If replstr is NULL, then that internally is changed to a nil-string, so 34 1.1.10.2 bouyer * that we can still pretend to do somewhat meaningful substitution. 35 1.1.10.2 bouyer * No value is returned. 36 1.1.10.2 bouyer */ 37 1.1.10.2 bouyer void 38 1.1.10.2 bouyer strnsubst(char **str, const char *match, const char *replstr, size_t maxsize) 39 1.1.10.2 bouyer { 40 1.1.10.2 bouyer char *s1, *s2, *this; 41 1.1.10.2 bouyer 42 1.1.10.2 bouyer s1 = *str; 43 1.1.10.2 bouyer if (s1 == NULL) 44 1.1.10.2 bouyer return; 45 1.1.10.2 bouyer /* 46 1.1.10.2 bouyer * If maxsize is 0 then set it to to the length of s1, because we have 47 1.1.10.2 bouyer * to duplicate s1. XXX we maybe should double-check whether the match 48 1.1.10.2 bouyer * appears in s1. If it doesn't, then we also have to set the length 49 1.1.10.2 bouyer * to the length of s1, to avoid modifying the argument. It may make 50 1.1.10.2 bouyer * sense to check if maxsize is <= strlen(s1), because in that case we 51 1.1.10.2 bouyer * want to return the unmodified string, too. 52 1.1.10.2 bouyer */ 53 1.1.10.2 bouyer if (maxsize == 0) { 54 1.1.10.2 bouyer match = NULL; 55 1.1.10.2 bouyer maxsize = strlen(s1) + 1; 56 1.1.10.2 bouyer } 57 1.1.10.2 bouyer s2 = calloc(maxsize, 1); 58 1.1.10.2 bouyer if (s2 == NULL) 59 1.1.10.2 bouyer err(1, "calloc"); 60 1.1.10.2 bouyer 61 1.1.10.2 bouyer if (replstr == NULL) 62 1.1.10.2 bouyer replstr = ""; 63 1.1.10.2 bouyer 64 1.1.10.2 bouyer if (match == NULL || replstr == NULL || maxsize == strlen(s1)) { 65 1.1.10.2 bouyer (void)strlcpy(s2, s1, maxsize); 66 1.1.10.2 bouyer goto done; 67 1.1.10.2 bouyer } 68 1.1.10.2 bouyer 69 1.1.10.2 bouyer for (;;) { 70 1.1.10.2 bouyer this = strstr(s1, match); 71 1.1.10.2 bouyer if (this == NULL) 72 1.1.10.2 bouyer break; 73 1.1.10.2 bouyer if ((strlen(s2) + strlen(s1) + strlen(replstr) - 74 1.1.10.2 bouyer strlen(match) + 1) > maxsize) { 75 1.1.10.2 bouyer (void)strlcat(s2, s1, maxsize); 76 1.1.10.2 bouyer goto done; 77 1.1.10.2 bouyer } 78 1.1.10.2 bouyer (void)strncat(s2, s1, (uintptr_t)this - (uintptr_t)s1); 79 1.1.10.2 bouyer (void)strcat(s2, replstr); 80 1.1.10.2 bouyer s1 = this + strlen(match); 81 1.1.10.2 bouyer } 82 1.1.10.2 bouyer (void)strcat(s2, s1); 83 1.1.10.2 bouyer done: 84 1.1.10.2 bouyer *str = s2; 85 1.1.10.2 bouyer return; 86 1.1.10.2 bouyer } 87 1.1.10.2 bouyer 88 1.1.10.2 bouyer #ifdef TEST 89 1.1.10.2 bouyer #include <stdio.h> 90 1.1.10.2 bouyer 91 1.1.10.2 bouyer int 92 1.1.10.2 bouyer main(void) 93 1.1.10.2 bouyer { 94 1.1.10.2 bouyer char *x, *y, *z, *za; 95 1.1.10.2 bouyer 96 1.1.10.2 bouyer x = "{}%$"; 97 1.1.10.2 bouyer strnsubst(&x, "%$", "{} enpury!", 255); 98 1.1.10.2 bouyer y = x; 99 1.1.10.2 bouyer strnsubst(&y, "}{}", "ybir", 255); 100 1.1.10.2 bouyer z = y; 101 1.1.10.2 bouyer strnsubst(&z, "{", "v ", 255); 102 1.1.10.2 bouyer za = z; 103 1.1.10.2 bouyer strnsubst(&z, NULL, za, 255); 104 1.1.10.2 bouyer if (strcmp(z, "v ybir enpury!") == 0) 105 1.1.10.2 bouyer (void)printf("strnsubst() seems to work!\n"); 106 1.1.10.2 bouyer else 107 1.1.10.2 bouyer (void)printf("strnsubst() is broken.\n"); 108 1.1.10.2 bouyer (void)printf("%s\n", z); 109 1.1.10.2 bouyer free(x); 110 1.1.10.2 bouyer free(y); 111 1.1.10.2 bouyer free(z); 112 1.1.10.2 bouyer free(za); 113 1.1.10.2 bouyer return 0; 114 1.1.10.2 bouyer } 115 1.1.10.2 bouyer #endif 116
Indexes created Tue Oct 21 06:10:07 GMT 2025