rs@mirror.TMC.COM (Rich Salz) (11/27/86)
There have been several regular-expression subroutines and one or two
filename-globbing routines in mod.sources. They handle lots of
complicated patterns. This small piece of code handles the *?[]\
wildcard characters the way the standard Unix(tm) shells do, with the
addition that "[^.....]" is an inverse character class -- it matches
any character not in the range ".....". Read the comments for more
info.
For my application, I had first ripped off a copy of the "glob" routine
from within the find(1) source, but that code is bad news: it recurses
on every character in the pattern. I'm putting this replacement in the
public domain. It's small, tight, and iterative. Compile with -DTEST
to get a test driver. After you're convinced it works, install in
whatever way is appropriate for you.
I would like to hear of bugs, but am not interested in additions; if I
were, I'd use the code I mentioned above.
No manpage or Makefile (else this would be in mod.sources :-).
#!/bin/sh
# This is a shell archive. Remove anything before this line,
# then unpack it by saving it in a file and typing "sh file".
# If all goes well, you will see the message "No problems found."
# Wrapped by mirror!rs on Wed Nov 26 19:06:08 EST 1986
# Exit status; set to 1 on "wc" errors or if would overwrite.
STATUS=0
# Contents: wildmat.c
echo x - wildmat.c
if test -f wildmat.c ; then
echo wildmat.c exists, putting output in $$wildmat.c
OUT=$$wildmat.c
STATUS=1
else
OUT=wildmat.c
fi
sed 's/^X//' > $OUT <<'@//E*O*F wildmat.c//'
X/*
X** Do shell-style pattern matching for ?, \, [], and * characters.
X** Might not be robust in face of malformed patterns; e.g., "foo[a-"
X** could cause a segmentation violation.
X**
X** Written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
X*/
X#define TRUE 1
X#define FALSE 0
Xstatic int
XStar(s, p)
X register char *s;
X register char *p;
X{
X while (wildmat(s, p) == FALSE)
X if (*++s == '\0')
X return(FALSE);
X return(TRUE);
X}
Xint
Xwildmat(s, p)
X register char *s;
X register char *p;
X{
X register int last;
X register int matched;
X register int reverse;
X for ( ; *p; s++, p++)
X switch (*p) {
X case '\\':
X /* Literal match with following character; fall through. */
X p++;
X default:
X if (*s != *p)
X return(FALSE);
X continue;
X case '?':
X /* Match anything. */
X if (*s == '\0')
X return(FALSE);
X continue;
X case '*':
X /* Trailing star matches everything. */
X return(*++p ? Star(s, p) : TRUE);
X case '[':
X /* [^....] means inverse character class. */
X if (reverse = p[1] == '^')
X p++;
X for (last = 0400, matched = FALSE; *++p && *p != ']'; last = *p)
X /* This next line requires a good C compiler. */
X if (*p == '-' ? *s <= *++p && *s >= last : *s == *p)
X matched = TRUE;
X if (matched == reverse)
X return(FALSE);
X continue;
X }
X return(*s == '\0');
X}
X#ifdef TEST
X#include <stdio.h>
Xextern char *gets();
Xmain()
X{
X char pattern[80];
X char text[80];
X while (TRUE) {
X printf("Enter pattern: ");
X if (gets(pattern) == NULL)
X break;
X while (TRUE) {
X printf("Enter text: ");
X if (gets(text) == NULL)
X exit(0);
X if (text[0] == '\0')
X /* Blank line; go back and get a new pattern. */
X break;
X printf(" %d\n", wildmat(text, pattern));
X }
X }
X exit(0);
X}
X#endif /* TEST */
@//E*O*F wildmat.c//
chmod u=rw,g=rw,o=rw $OUT
echo Inspecting for damage in transit...
temp=/tmp/sharin$$; dtemp=/tmp/sharout$$
trap "rm -f $temp $dtemp; exit" 0 1 2 3 15
cat > $temp <<\!!!
95 281 1828 wildmat.c
!!!
wc wildmat.c | sed 's=[^ ]*/==' | diff -b $temp - >$dtemp
if test -s $dtemp ; then
echo "Ouch [diff of wc output]:"
cat $dtemp
STATUS=1
elif test $STATUS = 0 ; then
echo "No problems found."
else
echo "WARNING -- PROBLEMS WERE FOUND..."
fi
exit $STATUS
--
--
Rich $alz "Hi, mom!"
Mirror Systems, Cambridge Massachusetts rs@mirror.TMC.COM
{mit-eddie, ihnp4, wjh12, cca, cbosgd, seismo}!mirror!rs