swab(3)			    Library Functions Manual			 swab(3)

NAME
     swab - swap adjacent bytes

LIBRARY
     Standard C library (libc, -lc)

SYNOPSIS
     #define _XOPEN_SOURCE	 /* See feature_test_macros(7) */
     #include <unistd.h>

     void swab(ssize_t n;
	       const void from[restrict n], void to[restrict n],
	       ssize_t n);

DESCRIPTION
     The swab() function copies n bytes from the array pointed to by from to the
     array pointed to by to, exchanging adjacent even and odd bytes.  This func-
     tion is used to exchange data between machines that have different low/high
     byte ordering.

     This function does nothing when n is negative.  When n is positive and odd,
     it handles n-1 bytes as above, and does something unspecified with the last
     byte.  (In other words, n should be even.)

RETURN VALUE
     The swab() function returns no value.

ATTRIBUTES
     For  an  explanation  of the terms used in this section, see attributes(7).
     allbox; lbx lb lb l l l.  Interface Attribute Value T{ swab() T}	Thread
     safety  MT-Safe

STANDARDS
     POSIX.1-2008.

HISTORY
     POSIX.1-2001, SVr4, 4.3BSD.

SEE ALSO
     bstring(3)

Linux man-pages 6.18		   2026-02-08				 swab(3)