NAME

       pmstrncat - 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 not 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  en‐
       tries 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).

Performance Co-Pilot                                   PCP                                          PMSTRNCAT(3)