sbase/libutil/concat.c
Michael Forney 3276fbea1c concat: Use plain read/write instead of buffered stdio
If we are just copying data from one file to another, we don't need to
fill a complete buffer, just read a chunk at a time, and write it to the
output.
2017-07-14 07:50:47 +02:00

24 lines
398 B
C

/* See LICENSE file for copyright and license details. */
#include <unistd.h>
#include "../util.h"
int
concat(int f1, const char *s1, int f2, const char *s2)
{
char buf[BUFSIZ];
ssize_t n;
while ((n = read(f1, buf, sizeof(buf))) > 0) {
if (writeall(f2, buf, n) < 0) {
weprintf("write %s:", s2);
return -2;
}
}
if (n < 0) {
weprintf("read %s:", s1);
return -1;
}
return 0;
}