0fa5e8dc42
corrupt memory. Simplifies the code in one or two places, also removes some code that looks like it was bogus or incomplete. Update strnsubst to have one or two extra conditions which maybe would make it more efficient, or at least more versatile. This is likely a no-op.
84 lines
1.9 KiB
C
84 lines
1.9 KiB
C
/* $xMach: strnsubst.c,v 1.3 2002/02/23 02:10:24 jmallett Exp $ */
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/*
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* Copyright (c) 2002 J. Mallett. All rights reserved.
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* You may do whatever you want with this file as long as
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* the above copyright and this notice remain intact, along
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* with the following statement:
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* For the man who taught me vi, and who got too old, too young.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <err.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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void strnsubst(char **, const char *, const char *, size_t);
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/*
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* Replaces str with a string consisting of str with match replaced with
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* replstr as many times as can be done before the constructed string is
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* maxsize bytes large. It does not free the string pointed to by str, it
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* is up to the calling program to be sure that the original contents of
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* str as well as the new contents are handled in an appropriate manner.
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* No value is returned.
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*/
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void
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strnsubst(char **str, const char *match, const char *replstr, size_t maxsize)
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{
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char *s1, *s2;
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s1 = *str;
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if (s1 == NULL)
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return;
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s2 = calloc(maxsize, 1);
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if (s2 == NULL)
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err(1, "calloc");
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if (match == NULL || replstr == NULL || maxsize == strlen(*str)) {
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strlcpy(s2, s1, maxsize);
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goto done;
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}
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for (;;) {
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char *this;
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this = strstr(s1, match);
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if (this == NULL)
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break;
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if ((strlen(s2) + ((uintptr_t)this - (uintptr_t)s1) +
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(strlen(replstr) - 1)) > maxsize) {
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strlcat(s2, s1, maxsize);
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goto done;
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}
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strncat(s2, s1, (uintptr_t)this - (uintptr_t)s1);
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strcat(s2, replstr);
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s1 = this + strlen(match);
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}
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strcat(s2, s1);
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done:
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*str = s2;
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return;
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}
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#ifdef TEST
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#include <stdio.h>
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int
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main(void)
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{
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char *x, *y;
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y = x = "{}{}{}";
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strnsubst(&x, "{}", "v ybir whyv! ", 12);
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if (strcmp(x, "v ybir whyv! ") == 0)
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printf("strnsubst() seems to work as expected.\n");
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printf("x: %s\ny: %s\n", x, y);
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free(x);
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return 0;
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}
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#endif
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