NAME
pattern_fill - Fill a buffer with copies of a pattern
pattern_check - Validate a buffer against copies of a pattern
SYNOPSIS
pattern_fill(char *buf, int buflen, char *pat, int patlen, int
patshift)
pattern_check(char *buf, int buflen, char *pat, int patlen, int
patshift)
DESCRIPTION
pattern_fill() fills a buffer of length buflen with repeated
occurrences of a pattern whose length is patlen. If buflen is not a
multiple of patlen, a partial pattern will be written in the last part
of the buffer. This implies that a buffer which is shorter than the
pattern length will receive only a partial pattern.
pattern_check() verifies that buf contains repeated occurrences of the
indicated pattern.
The patshift argument to pattern_fill() and pattern_shift() specify
that pat should be rotated (patshift % patlen) bytes to the left before
filling or comparing the buffer. Since the pattern is rotated by
(patshift % patlen), patshift may be greater than pathlen.
EXAMPLES
pattern_fill(buf, sizeof(buf), "abcde", 5, 0)
fill buf with repeated occurrences of "abcde"
pattern_check(buf, sizeof(buf), "abcde", 5, 0)
verify that buf consists of repeated occurrences of "abcde"
pattern_fill(buf, sizeof(buf), "abcde", 5, 3)
fill buf with repeated occurrences of "deabc"
DIAGNOSTICS
pattern_fill() always returns 0 - no validation of arguments is done.
pattern_check() returns -1 if the buffer does not contain repeated
occurrences of the indicated pattern (rotated patshift bytes) or 0
otherwise.
BUGS
None known.