[hackers] [sbase] Audit comm(1) || FRIGN

From: <git_AT_suckless.org>
Date: Wed, 11 Mar 2015 14:55:11 +0100 (CET)

commit e94f1678c5867331beac3fff82673ce57a34f300
Author: FRIGN <dev_AT_frign.de>
Date: Wed Mar 11 13:39:08 2015 +0100

    Audit comm(1)
    
    1) Use the LIMIT()-macro in util.h instead of defining our own.
    2) Drop nextline() and finish(), not needed anymore. Use
       fputs in printline instead of printf.
       --> BUGFIX: Finish exited with status 1, but actually should
                   exit with status 0 if ferror(f) == 0.
    3) Don't use /dev/fd/0 and use idiomatic <stdin> and fp = stdin
       instead.
    4) Refactor loop to use getline() instead of some handrolled
       nextline-function.
       --> BUGFIX: Line-length was limited to LINE_MAX before, now
                   it's factually unlimited.
    5) Combine diff >= 0 and diff <= 0 into one loop with a beginning
       continue-condition (diff && i == (diff < 0)).
    6) BUGFIX: If diff == 0, don't print one buffer after EOFing on the
               other.

diff --git a/comm.c b/comm.c
index a005882..fec5723 100644
--- a/comm.c
+++ b/comm.c
_AT_@ -5,8 +5,6 @@
 
 #include "util.h"
 
-#define CLAMP(x, l, h) MIN(h, MAX(l, x))
-
 static int show = 0x07;
 
 static void
_AT_@ -21,28 +19,7 @@ printline(int pos, char *line)
                 if (show & (0x1 << i))
                         putchar('\t');
         }
- printf("%s", line);
-}
-
-static char *
-nextline(char *buf, int n, FILE *f, char *name)
-{
- buf = fgets(buf, n, f);
- if (!buf && !feof(f))
- eprintf("%s: read error:", name);
- if (buf && !strchr(buf, '\n'))
- eprintf("%s: line too long\n", name);
- return buf;
-}
-
-static void
-finish(int pos, FILE *f, char *name)
-{
- char buf[LINE_MAX + 1];
-
- while (nextline(buf, sizeof(buf), f, name))
- printline(pos, buf);
- exit(1);
+ fputs(line, stdout);
 }
 
 static void
_AT_@ -54,9 +31,10 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
- int i, diff = 0;
         FILE *fp[2];
- char lines[2][LINE_MAX + 1];
+ size_t linelen[2] = { 0, 0 };
+ int i, diff = 0;
+ char *line[2] = { NULL, NULL };
 
         ARGBEGIN {
         case '1':
_AT_@ -71,36 +49,35 @@ main(int argc, char *argv[])
         if (argc != 2)
                 usage();
 
- for (i = 0; i < LEN(fp); i++) {
- if (argv[i][0] == '-' && !argv[i][1])
- argv[i] = "/dev/fd/0";
- if (!(fp[i] = fopen(argv[i], "r")))
+ for (i = 0; i < 2; i++) {
+ if (argv[i][0] == '-' && !argv[i][1]) {
+ argv[i] = "<stdin>";
+ fp[i] = stdin;
+ } else if (!(fp[i] = fopen(argv[i], "r"))) {
                         eprintf("fopen %s:", argv[i]);
+ }
         }
 
         for (;;) {
- if (diff <= 0) {
- lines[0][0] = '\0';
- if (!nextline(lines[0], sizeof(lines[0]),
- fp[0], argv[0])) {
- if (lines[1][0] != '\0')
- printline(1, lines[1]);
- finish(1, fp[1], argv[1]);
- }
- }
- if (diff >= 0) {
- lines[1][0] = '\0';
- if (!nextline(lines[1], sizeof(lines[1]),
- fp[1], argv[1])) {
- if (lines[0][0] != '\0')
- printline(0, lines[0]);
- finish(0, fp[0], argv[0]);
- }
+ for (i = 0; i < 2; i++) {
+ if (diff && i == (diff < 0))
+ continue;
+ if (getline(&line[i], &linelen[i], fp[i]) >= 0)
+ continue;
+ if (ferror(fp[i]))
+ eprintf("getline %s:", argv[i]);
+ if (diff && strlen(line[!i]))
+ printline(!i, line[!i]);
+ while (getline(&line[!i], &linelen[!i], fp[!i]) >= 0)
+ printline(!i, line[!i]);
+ if (ferror(fp[!i]))
+ eprintf("getline %s:", argv[!i]);
+ goto end;
                 }
- diff = strcmp(lines[0], lines[1]);
- diff = CLAMP(diff, -1, 1);
- printline((2-diff) % 3, lines[MAX(0, diff)]);
+ diff = strcmp(line[0], line[1]);
+ LIMIT(diff, -1, 1);
+ printline((2-diff) % 3, line[MAX(0, diff)]);
         }
-
+end:
         return 0;
 }
Received on Wed Mar 11 2015 - 14:55:11 CET