83 lines
2.1 KiB
C
Executable File
83 lines
2.1 KiB
C
Executable File
/********************************************************************\
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Name: strlcpy.c
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Created by: Stefan Ritt
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Contents: Contains strlcpy and strlcat which are versions of
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strcpy and strcat, but which avoid buffer overflows
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$Id:$
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\********************************************************************/
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#include <stdio.h>
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#include <string.h>
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#include "strlcpy.h"
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/*
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* Copy src to string dst of size siz. At most siz-1 characters
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* will be copied. Always NUL terminates (unless size == 0).
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* Returns strlen(src); if retval >= siz, truncation occurred.
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*/
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size_t strlcpy(char *dst, const char *src, size_t size)
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{
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char *d = dst;
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const char *s = src;
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size_t n = size;
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/* Copy as many bytes as will fit */
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if (n != 0 && --n != 0) {
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do {
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if ((*d++ = *s++) == 0)
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break;
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} while (--n != 0);
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}
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/* Not enough room in dst, add NUL and traverse rest of src */
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if (n == 0) {
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if (size != 0)
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*d = '\0'; /* NUL-terminate dst */
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while (*s++);
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}
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return (s - src - 1); /* count does not include NUL */
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}
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/*-------------------------------------------------------------------*/
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/*
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* Appends src to string dst of size siz (unlike strncat, siz is the
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* full size of dst, not space left). At most siz-1 characters
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* will be copied. Always NUL terminates (unless size <= strlen(dst)).
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* Returns strlen(src) + MIN(size, strlen(initial dst)).
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* If retval >= size, truncation occurred.
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*/
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size_t strlcat(char *dst, const char *src, size_t size)
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{
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char *d = dst;
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const char *s = src;
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size_t n = size;
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size_t dlen;
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/* Find the end of dst and adjust bytes left but don't go past end */
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while (n-- != 0 && *d != '\0')
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d++;
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dlen = d - dst;
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n = size - dlen;
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if (n == 0)
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return (dlen + strlen(s));
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while (*s != '\0') {
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if (n != 1) {
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*d++ = *s;
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n--;
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}
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s++;
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}
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*d = '\0';
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return (dlen + (s - src)); /* count does not include NUL */
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}
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/*-------------------------------------------------------------------*/
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