SWAB(3)

SWAB(3) | Library Functions Manual | SWAB(3)

# NAME

swab — swap adjacent bytes

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

#include <unistd.h>
void
swab(const void * restrict src, void * restrict dst, ssize_t len);

# DESCRIPTION

The function swab() copies len bytes from the location referenced by src to the location referenced by dst, swapping adjacent bytes.
If len is negative or zero, swab() does nothing. If len is odd, swab() copies len - 1 bytes and the disposition of the last byte is unspecified.

# SEE ALSO

bzero(3), memset(3)

# STANDARDS

The swab() function conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

# HISTORY

A swab() function appeared in Version 7 AT&T UNIX. It was originally documented to be “useful for carrying binary data between PDP11's and other machines”.
In NetBSD 6.0 the type of len was changed from size_t to ssize_t for POSIX compliance.

April 30, 2010 | NetBSD 8.3