uniq(1): skip() each input line only once

In uniq(1), skip() is very expensive.  We should only do it once per
input line.  Doing it more than once is redundant, anyway.

Thread: https://marc.info/?l=openbsd-tech&m=163950278018535&w=2

ok millert@

diff --git a/usr.bin/uniq/uniq.c b/usr.bin/uniq/uniq.c
index 7356d92..fa2b0e7 100644 (file)
--- a/usr.bin/uniq/uniq.c
+++ b/usr.bin/uniq/uniq.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uniq.c,v 1.29 2021/11/17 23:09:38 cheloha Exp $       */
+/*     $OpenBSD: uniq.c,v 1.30 2021/12/24 17:59:28 cheloha Exp $       */
 /*     $NetBSD: uniq.c,v 1.7 1995/08/31 22:03:48 jtc Exp $     */
 
 /*
@@ -57,7 +57,7 @@ __dead void   usage(void);
 int
 main(int argc, char *argv[])
 {
-       char *prevline, *t1, *t2, *thisline;
+       char *p, *prevline, *t, *thisline, *tmp;
        FILE *ifp = NULL, *ofp = NULL;
        size_t prevsize, thissize, tmpsize;
        ssize_t len;
@@ -142,6 +142,10 @@ main(int argc, char *argv[])
        }
        if (prevline[len - 1] == '\n')
                prevline[len - 1] = '\0';
+       if (numfields || numchars)
+               p = skip(prevline);
+       else
+               p = prevline;
        
        thissize = 0;
        thisline = NULL;
@@ -150,20 +154,20 @@ main(int argc, char *argv[])
                        thisline[len - 1] = '\0';
 
                /* If requested get the chosen fields + character offsets. */
-               if (numfields || numchars) {
-                       t1 = skip(thisline);
-                       t2 = skip(prevline);
-               } else {
-                       t1 = thisline;
-                       t2 = prevline;
-               }
+               if (numfields || numchars)
+                       t = skip(thisline);
+               else
+                       t = thisline;
 
                /* If different, print; set previous to new value. */
-               if ((iflag ? strcasecmp : strcmp)(t1, t2)) {
+               if ((iflag ? strcasecmp : strcmp)(p, t)) {
                        show(ofp, prevline);
-                       t1 = prevline;
+                       tmp = prevline;
                        prevline = thisline;
-                       thisline = t1;
+                       thisline = tmp;
+                       tmp = p;
+                       p = t;
+                       t = tmp;
                        tmpsize = prevsize;
                        prevsize = thissize;
                        thissize = tmpsize;