KCGI_BUF_WRITE(3) Library Functions Manual KCGI_BUF_WRITE(3)

kcgi_buf_writeput binary data into a kcgi buffer

library “libkcgi”

#include <sys/types.h>
#include <stdarg.h>
#include <stdint.h>
#include <kcgi.h>

enum kcgi_err
kcgi_buf_write(const char *buf, size_t sz, void *arg);

Appends binary data buf of size sz to arg, which is cast to a struct kcgi_buf *. Buffers must be initialised to zero with memset(3) prior to first use. The buffer will always be NUL-terminated. Does nothing if buf is NULL or sz is zero.

The struct kcgi_buf structure has the following fields:

char *buf
Buffer contents. This is always NUL-terminated, even if the data is binary. This buffer must be passed to free(3) after use.
size_t maxsz
Allocated buffer size.
size_t sz
Buffer current length not including the NUL terminator.
size_t growsz
Amount of "slop" space in the buffer if it's reallocated. If set to zero, defaults to 1 KB.

These functions return an enum kcgi_err indicating the error state: KCGI_OK for no error, KCGI_ENOMEM for an internal memory allocation failure.

The following creates a simple NUL-terminated buffer. It does not perform any error checking.

struct kcgi_buf buf;

memset(&buf, 0, sizeof(struct kcgi_buf));
kcgi_buf_write("xyzzy", 5, &buf);
puts(buf.buf); /* Emits "xyzzy" */
free(buf.buf);

kcgi_buf_printf(3), kcgi_buf_putc(3), kcgi_buf_puts(3)

Written by Kristaps Dzonsons <kristaps@bsd.lv>.

March 22, 2020 OpenBSD 6.7