1 /* $xMach: strnsubst.c,v 1.3 2002/02/23 02:10:24 jmallett Exp $ */
4 * Copyright (c) 2002 J. Mallett. All rights reserved.
5 * You may do whatever you want with this file as long as
6 * the above copyright and this notice remain intact, along
7 * with the following statement:
8 * For the man who taught me vi, and who got too old, too young.
10 * $FreeBSD: src/usr.bin/xargs/strnsubst.c,v 1.5.2.1 2002/06/17 04:44:46 jmallett Exp $
11 * $DragonFly: src/usr.bin/xargs/strnsubst.c,v 1.2 2003/06/17 04:29:34 dillon Exp $
20 void strnsubst(char **, const char *, const char *, size_t);
23 * Replaces str with a string consisting of str with match replaced with
24 * replstr as many times as can be done before the constructed string is
25 * maxsize bytes large. It does not free the string pointed to by str, it
26 * is up to the calling program to be sure that the original contents of
27 * str as well as the new contents are handled in an appropriate manner.
28 * If replstr is NULL, then that internally is changed to a nil-string, so
29 * that we can still pretend to do somewhat meaningful substitution.
30 * No value is returned.
33 strnsubst(char **str, const char *match, const char *replstr, size_t maxsize)
40 s2 = calloc(maxsize, 1);
47 if (match == NULL || replstr == NULL || maxsize == strlen(s1)) {
48 strlcpy(s2, s1, maxsize);
53 this = strstr(s1, match);
56 if ((strlen(s2) + ((uintptr_t)this - (uintptr_t)s1) +
57 (strlen(replstr) - 1)) > maxsize && *replstr != '\0') {
58 strlcat(s2, s1, maxsize);
61 strncat(s2, s1, (uintptr_t)this - (uintptr_t)s1);
63 s1 = this + strlen(match);
80 strnsubst(&x, "{}", "v ybir whyv! ", 12);
81 if (strcmp(x, "v ybir whyv! ") == 0)
82 printf("strnsubst() seems to work as expected.\n");
83 printf("x: %s\ny: %s\n", x, y);