[hackers] [sbase] Implement concat() using read(2) and write(2) || sin

From: <git_AT_suckless.org>
Date: Thu, 13 Nov 2014 15:56:11 +0100

commit 5773a8f22b400601ec82cc6b199b160a1d1cca22
Author: sin <sin_AT_2f30.org>
Date: Thu Nov 13 14:14:20 2014 +0000

    Implement concat() using read(2) and write(2)
    
    This forces the data to be read as soon as they are available
    and a simple cat(1) when stdin is referring to a tty works as
    expected.

diff --git a/util/concat.c b/util/concat.c
index 939219d..a276fbb 100644
--- a/util/concat.c
+++ b/util/concat.c
_AT_@ -1,5 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 #include <stdio.h>
+#include <unistd.h>
 
 #include "../text.h"
 #include "../util.h"
_AT_@ -8,14 +9,12 @@ void
 concat(FILE *fp1, const char *s1, FILE *fp2, const char *s2)
 {
         char buf[BUFSIZ];
- size_t n;
+ ssize_t n;
 
- while ((n = fread(buf, 1, sizeof buf, fp1)) > 0) {
- if (fwrite(buf, 1, n, fp2) != n)
+ while ((n = read(fileno(fp1), buf, sizeof buf)) > 0) {
+ if (write(fileno(fp2), buf, n) != n)
                         eprintf("%s: write error:", s2);
- if (feof(fp1))
- break;
         }
- if (ferror(fp1))
+ if (n < 0)
                 eprintf("%s: read error:", s1);
 }
Received on Thu Nov 13 2014 - 15:56:11 CET