NAME

       libbsd — utility functions from BSD systems

DESCRIPTION

       The  libbsd  library  provides  a  set  of 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_init(3) 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>
       <inttypes.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(3)
             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”).

       fgetwln(3)
             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 fgetwc(3) instead, which is available in many systems and required
             by ISO/IEC 9899:1999 (“ISO C99”) and IEEE Std 1003.1-2001 (“POSIX.1”).

       funopen(3)
             Unportable, requires assistance from the stdio layer or some hook framework.  On  GNU  systems  the
             fopencookie(3)  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(3)
       MD5Update(3)
       MD5Pad(3)
       MD5Final(3)
       MD5Transform(3)
       MD5End(3)
       MD5File(3)
       MD5FileChunk(3)
       MD5Data(3)
             The set of MD5 digest functions are now provided by the libmd companion library, so it  is  advised
             to use that instead.
       explicit_bzero(3)
             This function is provided by glibc 2.25.
       reallocarray(3)
             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),    strtoi(3bsd),    strtonum(3bsd),
       strtou(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.

Debian                                            May 21, 2018                                         LIBBSD(7)