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`dprintf`: print formatted text directly to a file descriptor
===============================================================
---
date: "2013-10-12"
license: WTFPL-2
---
This already existed as `dprintf(3)`. I now feel stupid for having
Implemented `fd_printf`.
The original post is as follows:
----
I wrote this while debugging some code, and thought it might be useful
to others:
#define _GNU_SOURCE /* vasprintf() */
#include <stdarg.h> /* va_start()/va_end() */
#include <stdio.h> /* vasprintf() */
#include <stdlib.h> /* free() */
#include <unistd.h> /* write() */
int
fd_printf(int fd, const char *format, ...)
{
va_list arg;
int len;
char *str;
va_start(arg, format);
len = vasprintf(&str, format, arg);
va_end(arg);
write(fd, str, len);
free(str);
return len;
}
It is a version of `printf` that prints to a file descriptor—where
`fprintf` prints to a `FILE*` data structure.
The appeal of this is that `FILE*` I/O is buffered—which means mixing
it with raw file descriptor I/O is going to produce weird results.
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