uniq(1): freopen(3) stdin, stdout

uniq(1) defaults to stdin and stdout, has exactly one input and one
output, and permits the user to replace the default input and/or the
default output with a given file.

freopen(3) is the right idiom in this context.  Get rid of file() and
the extra FILE pointers.  Switch from fprintf(3) to printf(3).

While here, const the "str" argument to show().

Thread: https://marc.info/?l=openbsd-tech&m=164078603312936&w=2

ok millert@

diff --git a/usr.bin/uniq/uniq.c b/usr.bin/uniq/uniq.c
index fa2b0e7..72474bf 100644 (file)
--- a/usr.bin/uniq/uniq.c
+++ b/usr.bin/uniq/uniq.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uniq.c,v 1.30 2021/12/24 17:59:28 cheloha Exp $       */
+/*     $OpenBSD: uniq.c,v 1.31 2022/01/01 02:20:38 cheloha Exp $       */
 /*     $NetBSD: uniq.c,v 1.7 1995/08/31 22:03:48 jtc Exp $     */
 
 /*
@@ -48,8 +48,7 @@
 int cflag, dflag, iflag, uflag;
 int numchars, numfields, repeats;
 
-FILE   *file(char *, char *);
-void    show(FILE *, char *);
+void    show(const char *);
 char   *skip(char *);
 void    obsolete(char *[]);
 __dead void    usage(void);
@@ -58,7 +57,6 @@ int
 main(int argc, char *argv[])
 {
        char *p, *prevline, *t, *thisline, *tmp;
-       FILE *ifp = NULL, *ofp = NULL;
        size_t prevsize, thissize, tmpsize;
        ssize_t len;
        int ch;
@@ -112,21 +110,15 @@ main(int argc, char *argv[])
        if (!dflag && !uflag)
                dflag = uflag = 1;
 
-       switch (argc) {
-       case 0:
-               ifp = stdin;
-               ofp = stdout;
-               break;
-       case 1:
-               ifp = file(argv[0], "r");
-               ofp = stdout;
-               break;
-       case 2:
-               ifp = file(argv[0], "r");
-               ofp = file(argv[1], "w");
-               break;
-       default:
+       if (argc > 2)
                usage();
+       if (argc >= 1 && strcmp(argv[0], "-") != 0) {
+               if (freopen(argv[0], "r", stdin) == NULL)
+                       err(1, "%s", argv[0]);
+       }
+       if (argc == 2 && strcmp(argv[1], "-") != 0) {
+               if (freopen(argv[1], "w", stdout) == NULL)
+                       err(1, "%s", argv[1]);
        }
 
        if (pledge("stdio", NULL) == -1)
@@ -134,9 +126,9 @@ main(int argc, char *argv[])
 
        prevsize = 0;
        prevline = NULL;
-       if ((len = getline(&prevline, &prevsize, ifp)) == -1) {
+       if ((len = getline(&prevline, &prevsize, stdin)) == -1) {
                free(prevline);
-               if (ferror(ifp))
+               if (ferror(stdin))
                        err(1, "getline");
                exit(0);
        }
@@ -149,7 +141,7 @@ main(int argc, char *argv[])
        
        thissize = 0;
        thisline = NULL;
-       while ((len = getline(&thisline, &thissize, ifp)) != -1) {
+       while ((len = getline(&thisline, &thissize, stdin)) != -1) {
                if (thisline[len - 1] == '\n')
                        thisline[len - 1] = '\0';
 
@@ -161,7 +153,7 @@ main(int argc, char *argv[])
 
                /* If different, print; set previous to new value. */
                if ((iflag ? strcasecmp : strcmp)(p, t)) {
-                       show(ofp, prevline);
+                       show(prevline);
                        tmp = prevline;
                        prevline = thisline;
                        thisline = tmp;
@@ -176,10 +168,10 @@ main(int argc, char *argv[])
                        ++repeats;
        }
        free(thisline);
-       if (ferror(ifp))
+       if (ferror(stdin))
                err(1, "getline");
 
-       show(ofp, prevline);
+       show(prevline);
        free(prevline);
 
        exit(0);
@@ -191,13 +183,13 @@ main(int argc, char *argv[])
  *     of the line.
  */
 void
-show(FILE *ofp, char *str)
+show(const char *str)
 {
        if ((dflag && repeats) || (uflag && !repeats)) {
                if (cflag)
-                       fprintf(ofp, "%4d %s\n", repeats + 1, str);
+                       printf("%4d %s\n", repeats + 1, str);
                else
-                       fprintf(ofp, "%s\n", str);
+                       printf("%s\n", str);
        }
 }
 
@@ -233,18 +225,6 @@ skip(char *str)
        return (str);
 }
 
-FILE *
-file(char *name, char *mode)
-{
-       FILE *fp;
-
-       if (strcmp(name, "-") == 0)
-               return(*mode == 'r' ? stdin : stdout);
-       if ((fp = fopen(name, mode)) == NULL)
-               err(1, "%s", name);
-       return (fp);
-}
-
 void
 obsolete(char *argv[])
 {