upper/lower case filter

[Joel West]

I had to compare two versions of a file; one was mostly uppercase,
while the 2nd had a lot of changes that were only case changes.

While I wish "diff" had an ignore case option, it doesn't.  So
I spent 20 minutes and wrote this. (no cracks about my slowness).
It converts upper to lower or vice versa, and should work on just
about any system.

Note on names: "case" was out for obvious reasons.  "uc" implies
upper more than "lc" implies lower, to my limited mind.  And there's
already ld, ln, ls, and I used the alias "lf", so "u" looked better.

***FLAME SUIT ON***
If BSD 4.2 or V/2.0 already does this, MAIL but do not FOLLOW-UP.
***FLAME SUIT OFF**

As always, we welcome comments by spokespersons with opposing viewpoints.

	Joel West	 CACI, Inc. Federal, La Jolla
	{cbosgd,floyd,ihnp4,pyramid,sdcsvax,ucla-cs}!gould9!joel
	gould9!joel at nosc.ARPA

------------------cut me---------------beat me-------------slice me-----------
#!/bin/sh
# This is a shell archive, meaning:
# 1. Remove everything above the #!/bin/sh line.
# 2. Save the resulting text in a file.
# 3. Execute the file with /bin/sh (not csh) to create the files:
#	uc.c
# This archive created: Sat Nov  9 11:24:26 1985
export PATH; PATH=/bin:$PATH
echo shar: extracting "'uc.c'" '(910 characters)'
if test -f 'uc.c'
then
	echo shar: over-writing existing file "'uc.c'"
fi
cat << \SHAR_EOF > 'uc.c'
/* uc.c: change to upper (or lower) case
   Joel West 11/9/85 <ihnp4!gould9!joel, gould9!joel at NOSC.arpa>
*/

#include <stdio.h>
#include <ctype.h>

int optl=0;

main(argc,argv)
int argc;
char **argv;
{	char *p,c;
	int i, up2low, fileargs;

	up2low = 'a'-'A';

	i=1;

	for (i=1; i<argc; i++)
	{   if (*argv[i] != '-')
		break;
	    p = argv[i];
	    if (*++p == 'l')
		optl++;
	    else
	    {	fprintf(stderr, "usage: %s [-l] [file1 file2 ...]\n", argv[0]);
		exit (1);
	    }
	}

	fileargs = i<argc;	/* there are file arguments */
	if (! fileargs)		/* minimum one trip for stdin */
	    i = argc-1;
	for ( ; i<argc; i++)	
	{   if (fileargs)
	    {   if (freopen(argv[i], "r", stdin) == NULL)
		{   perror(argv[i]);
		    continue;
		}
	    }
	    while ((c=getchar()) != EOF)
	    {	if (optl)
		{   if (isupper(c))
			c += up2low;
		}
		else
		{   if (islower(c))
			c -= up2low;
		}
		putchar(c);
	    }
	}
}
SHAR_EOF
if test 910 -ne "`wc -c 'uc.c'`"
then
	echo shar: error transmitting "'uc.c'" '(should have been 910 characters)'
fi
#	End of shell archive
exit 0