[src/trunk]: src/usr.bin/unexpand Fix a handful of bugs in unexpand(1):

[dyoung <dyoung%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c91828b3e931
branches:  trunk
changeset: 459496:c91828b3e931
user:      dyoung <dyoung%NetBSD.org@localhost>
date:      Fri Sep 13 16:53:05 2019 +0000

description:
Fix a handful of bugs in unexpand(1):

1. -a and -t were mutually exclusive when they should not be.

2. `unexpand -t n` did not treat a file like there were stops at n, 2
   n, 3 n, 4 n, and so on.  So expanded tabs after column 4 were not
   collapsed.

3. a debug fprintf wrote every tabstop set with `-t` to the standard
   error stream.

TBD write some tests.

diffstat:

 usr.bin/unexpand/unexpand.c |  29 ++++++++++++++---------------
 1 files changed, 14 insertions(+), 15 deletions(-)

diffs (77 lines):

diff -r 7b66461c37f4 -r c91828b3e931 usr.bin/unexpand/unexpand.c
--- a/usr.bin/unexpand/unexpand.c       Fri Sep 13 14:19:13 2019 +0000
+++ b/usr.bin/unexpand/unexpand.c       Fri Sep 13 16:53:05 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: unexpand.c,v 1.15 2016/02/03 05:32:14 christos Exp $   */
+/*     $NetBSD: unexpand.c,v 1.16 2019/09/13 16:53:05 dyoung Exp $     */
 
 /*-
  * Copyright (c) 1980, 1993
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)unexpand.c 8.1 (Berkeley) 6/6/93";
 #endif
-__RCSID("$NetBSD: unexpand.c,v 1.15 2016/02/03 05:32:14 christos Exp $");
+__RCSID("$NetBSD: unexpand.c,v 1.16 2019/09/13 16:53:05 dyoung Exp $");
 #endif /* not lint */
 
 /*
@@ -86,13 +86,9 @@
        while ((c = getopt(argc, argv, "at:")) != -1) {
                switch (c) {
                case 'a':
-                       if (nstops)
-                               usage();
-                       all++;
+                       all = 1;
                        break;
                case 't':
-                       if (all)
-                               usage();
                        while ((tab = strsep(&optarg, ", \t")) != NULL) {
                                if (*tab == '\0')
                                        continue;
@@ -121,9 +117,6 @@
        argc -= optind;
        argv += optind;
 
-       for (i = 0; i < nstops; i++)
-               fprintf(stderr, "%lu %zu\n", i, tabstops[i]);
-
        do {
                if (argc > 0) {
                        if (freopen(argv[0], "r", stdin) == NULL)
@@ -150,8 +143,11 @@
                        dcol++;
                        continue;
                } else if (*p == '\t') {
-                       if (nstops == 0) {
-                               dcol = (1 + dcol / DSTOP) * DSTOP;
+                       if (nstops <= 1) {
+                               size_t stop = (nstops == 0)
+                                   ? DSTOP
+                                   : tabstops[0];
+                               dcol = (1 + dcol / stop) * stop;
                                continue;
                        } else {
                                for (n = 0; n < nstops &&
@@ -165,13 +161,16 @@
                }
 
                /* Output our tabs */
-               if (nstops == 0) {
-                       while (((ocol + DSTOP) / DSTOP) <= (dcol / DSTOP)) {
+               if (nstops <= 1) {
+                       size_t stop = (nstops == 0)
+                           ? DSTOP
+                           : tabstops[0];
+                       while (((ocol + stop) / stop) <= (dcol / stop)) {
                                if (dcol - ocol < 2)
                                        break;
                                if (putchar('\t') == EOF)
                                        goto out;
-                               ocol = (1 + ocol / DSTOP) * DSTOP;
+                               ocol = (1 + ocol / stop) * stop;
                        }
                } else {
                        for (n = 0; n < nstops && tabstops[n] <= ocol; n++)