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.