colrm: gotos, long options and argument checking

Unnecessary goto jumps where replaced by a simple function, and
two loops. Long options support help and version, and the two
arguments this command has are now validated with strtoul_or_err.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

1 files changed, 99 insertions, 46 deletions

diff --git a/text-utils/colrm.c b/text-utils/colrm.c
index e8b1ea4a4..d454643a0 100644
--- a/text-utils/colrm.c
+++ b/text-utils/colrm.c
@@ -40,67 +40,80 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <getopt.h>
 
 #include "nls.h"
 #include "widechar.h"
+#include "strutils.h"
+#include "c.h"
 
 /*
 COLRM removes unwanted columns from a file
 	Jeff Schriebman  UC Berkeley 11-74
 */
 
-int
-main(int argc, char **argv)
+static void __attribute__ ((__noreturn__)) usage(FILE * out)
 {
-	register int ct, first, last;
-	register wint_t c;
-	int i, w;
+	fprintf(out, _("\nUsage:\n"
+		       " %s [startcol [endcol]]\n"),
+		       program_invocation_short_name);
+
+	fprintf(out, _("\nOptions:\n"
+		       " -V, --version   output version information and exit\n"
+		       " -h, --help      display this help and exit\n\n"));
+
+	fprintf(out, _("%s reads from standard input and writes to standard output\n\n"),
+		       program_invocation_short_name);
+
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int process_input(unsigned long first, unsigned long last)
+{
+	unsigned long ct = 0;
+	wint_t c;
+	unsigned long i;
+	int w;
 	int padding;
 
-	setlocale(LC_ALL, "");
+	for (;;) {
+		c = getwc(stdin);
+		if (c == WEOF)
+			return 0;
+		if (c == '\t')
+			w = ((ct + 8) & ~7) - ct;
+		else if (c == '\b')
+			w = (ct ? ct - 1 : 0) - ct;
+		else {
+			w = wcwidth(c);
+			if (w < 0)
+				w = 0;
+		}
+		ct += w;
+		if (c == '\n') {
+			putwc(c, stdout);
+			ct = 0;
+			continue;
 
-	first = 0;
-	last = 0;
-	if (argc > 1)
-		first = atoi(*++argv);
-	if (argc > 2)
-		last = atoi(*++argv);
-
-start:
-	ct = 0;
-loop1:
-	c = getwc(stdin);
-	if (c == WEOF)
-		goto fin;
-	if (c == '\t')
-		w = ((ct + 8) & ~7) - ct;
-	else if (c == '\b')
-		w = (ct ? ct - 1 : 0) - ct;
-	else {
-		w = wcwidth(c);
-		if (w < 0)
-			w = 0;
-	}
-	ct += w;
-	if (c == '\n') {
-		putwc(c, stdout);
-		goto start;
-	}
-	if (!first || ct < first) {
-		putwc(c, stdout);
-		goto loop1;
+		}
+		if (!first || ct < first) {
+			putwc(c, stdout);
+			continue;
+		}
+		break;
 	}
-	for (i = ct-w+1; i < first; i++)
+
+	for (i = ct - w + 1; i < first; i++)
 		putwc(' ', stdout);
 
-/* Loop getting rid of characters */
+	/* Loop getting rid of characters */
 	while (!last || ct < last) {
 		c = getwc(stdin);
 		if (c == WEOF)
-			goto fin;
+			return 0;
 		if (c == '\n') {
 			putwc(c, stdout);
-			goto start;
+			return 1;
 		}
 		if (c == '\t')
 			ct = (ct + 8) & ~7;
@@ -116,25 +129,65 @@ loop1:
 
 	padding = 0;
 
-/* Output last of the line */
+	/* Output last of the line */
 	for (;;) {
 		c = getwc(stdin);
 		if (c == WEOF)
 			break;
 		if (c == '\n') {
 			putwc(c, stdout);
-			goto start;
+			return 1;
 		}
 		if (padding == 0 && last < ct) {
-			for (i = last; i <ct; i++)
+			for (i = last; i < ct; i++)
 				putwc(' ', stdout);
 			padding = 1;
 		}
 		putwc(c, stdout);
 	}
-fin:
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned long first = 0, last = 0;
+	int opt;
+
+	static const struct option longopts[] = {
+		{"version", no_argument, 0, 'V'},
+		{"help", no_argument, 0, 'h'},
+		{NULL, 0, 0, 0}
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	while ((opt =
+		getopt_long(argc, argv, "bfhl:pxVH", longopts,
+			    NULL)) != -1)
+		switch (opt) {
+		case 'V':
+			printf(_("%s from %s\n"),
+			       program_invocation_short_name,
+			       PACKAGE_STRING);
+			return EXIT_SUCCESS;
+		case 'h':
+			usage(stdout);
+		default:
+			usage(stderr);
+		}
+
+	if (argc > 1)
+		first = strtoul_or_err(*++argv, _("first argument"));
+	if (argc > 2)
+		last = strtoul_or_err(*++argv, _("second argument"));
+
+	while (process_input(first, last))
+		;
+
 	fflush(stdout);
 	if (ferror(stdout) || fclose(stdout))
-		return 1;
-	return 0;
+		return EXIT_FAILURE;
+	return EXIT_SUCCESS;
 }