uniq(1) defaults to using stdin and stdout, has exactly one input and
one output, and allows changing the input and/or output to a given
file.
So, freopen(3) is the idiomatic thing to use here. It simplifies and
shortens the code. Then we don't need the file() function, we don't
need additional FILE pointers, and we can just use printf(3).
While here, const the "str" argument to show().
ok?
Index: uniq.c
===================================================================
RCS file: /cvs/src/usr.bin/uniq/uniq.c,v
retrieving revision 1.30
diff -u -p -r1.30 uniq.c
--- uniq.c 24 Dec 2021 17:59:28 -0000 1.30
+++ uniq.c 29 Dec 2021 13:39:59 -0000
@@ -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);
}
}
@@ -231,18 +223,6 @@ skip(char *str)
len = 1;
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
