NAME

     libbsd — utility functions from BSD systems

DESCRIPTION

     The libbsd library provides a set if compatibility macros and functions commonly found on BSD-based
     systems.  Its purpose is to make those available on non-BSD based systems to ease portability.

     The library can be used in an overlay mode, which is the preferred way, so that the code is portable and
     requires no modification to the original BSD code.  This can be done easily with the pkg-config(3) library
     named libbsd-overlay.  Or by adding the system-specific include directory with the bsd/ suffix to the list
     of system include paths.  With gcc this could be -isystem ${includedir}/bsd.  In addition the
     LIBBSD_OVERLAY pre-processor variable needs to be defined.  The includes in this case should be the usual
     system ones, such as <unistd.h>.

     The other way to use the library is to use the namespaced headers, this is less portable as it makes using
     libbsd mandatory and it will not work on BSD-based systems, and requires modifying original BSD code.  This
     can be done with the pkg-config(3) library named libbsd.  The includes in this case should be namespaced
     with bsd/, such as <bsd/unistd.h>.

     The package also provides a bsd-ctor static library that can be used to inject automatic constructors into
     a program so that the setproctitle() function gets invoked automatically at startup time.  This can be done
     with the pkg-config(3) library named libbsd-ctor.

HEADERS

     The following are the headers provided by libbsd, that extend the standard system headers.  They can work
     in normal or overlay modes, for the former they need to be prefixed with bsd/.

     <bitstring.h>
     <err.h>
     <getopt.h>
     <libutil.h>
     <md5.h>
     <netinet/ip_icmp.h>
     <nlist.h>
     <readpassphrase.h>
     <stdio.h>
     <stdlib.h>
     <string.h>
     <stringlist.h>
     <sys/bitstring.h>
     <sys/cdefs.h>
     <sys/endian.h>
     <sys/poll.h>
     <sys/queue.h>
     <sys/time.h>
     <sys/tree.h>
     <timeconv.h>
     <unistd.h>
     <vis.h>
     <wchar.h>

     The following is a libbsd specific convenience header, that includes some of the extended headers.  It only
     works in non-overlay mode.

     <bsd/bsd.h>

DEPRECATED

     Some functions have been deprecated, they will emit warnings at compile time and possibly while being
     linked at run-time.  This might be due to the functions not being portable at all to other systems, making
     the package not buildable there; not portable in a correct or non-buggy way; or because there are better
     more portable replacements now.

     This is the list of currently deprecated macros and functions:

     fgetln()
           Unportable, requires assistance from the stdio layer.  An implementation has to choose between
           leaking buffers or being reentrant for a limited amount of streams (this implementation chose the
           latter with a limit of 32).  Use getline(3) instead, which is available in many systems and required
           by IEEE Std 1003.1-2008 (“POSIX.1”).

     funopen()
           Unportable, requires assistance from the stdio layer or some hook framework.  On GNU systems the
           fopencookie() function can be used.  Otherwise the code needs to be prepared for neither of these
           functions being available.

SUPERSEDED

     Some functions have been superseded by implementations in other system libraries, and might disappear on
     the next SONAME bump, assuming those other implementation have widespread deployment, or the
     implementations are present in all major libc for example.

     MD5Init()
     MD5Update()
     MD5Pad()
     MD5Final()
     MD5Transform()
     MD5End()
     MD5File()
     MD5FileChunk()
     MD5Data()
           The set of MD5 digest functions are now provided by the libmd companion library, so it is advised to
           use that instead.
     explicit_bzero()
           This function is provided by glibc 2.25.
     reallocarray()
           This function is provided by glibc 2.26.

SEE ALSO

     arc4random(3bsd), bitstring(3bsd), byteorder(3bsd), closefrom(3bsd), errc(3bsd), expand_number(3bsd),
     explicit_bzero(3bsd), fgetln(3bsd), fgetwln(3bsd), flopen(3bsd), fmtcheck(3bsd), fparseln(3bsd),
     fpurge(3bsd), funopen(3bsd), getbsize(3bsd), getpeereid(3bsd), getprogname(3bsd), heapsort(3bsd),
     humanize_number(3bsd), md5(3bsd), nlist(3bsd), pidfile(3bsd), queue(3bsd), radixsort(3bsd),
     readpassphrase(3bsd), reallocarray(3bsd), reallocf(3bsd), setmode(3bsd), setproctitle(3bsd),
     stringlist(3bsd), strlcpy(3bsd), strmode(3bsd), strnstr(3bsd), strtonum(3bsd), timeradd(3bsd),
     timeval(3bsd), tree(3bsd), unvis(3bsd), vis(3bsd), wcslcpy(3bsd).

HISTORY

     The libbsd project started in the Debian GNU/kFreeBSD port as a way to ease porting code from FreeBSD to
     the GNU-based system.  Pretty early on it was generalized and a project created on FreeDesktop.org for
     other distributions and projects to use.

     It is now distributed as part of most non-BSD distributions.