pmstrncat - Man Page
safe string concatenation
C Synopsis
#include <pcp/pmapi.h>
int pmstrncat(char *dest, size_t destlen, char *src);
cc ... -lpcp
Description
pmstrncat is safe string concatenation routine with semantics similar to strncat(3).
The main differences between pmstrncat and strncat(3) are:
- src must be null-byte terminated for pmstrncat
- destlen is the length of the destination buffer (dest) for pmstrncat, not the maximum number of non-null bytes to copy from src as it is for strncat
- the length argument has the same semantics for pmstrncat and pmstrncpy(3), unlike strncat(3) and strncpy(3).
- the return value from pmstrncat is useful
- the order of the arguments for pmstrncat has been deliberately changed from the order of the arguments for strncat(3) to avoid accidental misuse that a compiler can easily detect
On success, pmstrncat returns 0, else -1 indicates that src is too big and the result been truncated to ensure dest has no been overrun.
History
strncat(3) first appeared in Edition 7 AT&T Unix around 1979. It was specifically crafted to construct file pathnames (which needed to be null-byte terminated) from component names from on-disk directory entries that were of a fixed maximum size and may have zero, one or more trailing null-bytes
The subsequent attempts to use strncat(3) for more generally string concatenation operations has been fraught with abuse and security issues; pmstrncat is an attempt to address these problems.
See Also
PMAPI(3), pmstrncpy(3), strncat(3) and strncpy(3).