Return to shell.m4 CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / libnet / m4

Annotation of embedaddon/libnet/m4/shell.m4, revision 1.1.1.1

1.1       misho       1: # Check for a working shell.
                      2: 
                      3: # Copyright (C) 2000-2001, 2007, 2009-2017 Free Software Foundation, Inc.
                      4: # This program is free software; you can redistribute it and/or modify
                      5: # it under the terms of the GNU General Public License as published by
                      6: # the Free Software Foundation; either version 3, or (at your option)
                      7: # any later version.
                      8: 
                      9: # This program is distributed in the hope that it will be useful,
                     10: # but WITHOUT ANY WARRANTY; without even the implied warranty of
                     11: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     12: # GNU General Public License for more details.
                     13: 
                     14: # You should have received a copy of the GNU General Public License
                     15: # along with this program; if not, write to the Free Software
                     16: # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
                     17: # 02111-1307, USA.
                     18: 
                     19: # AC_PROG_SHELL
                     20: # -------------
                     21: # Check for a working (i.e. POSIX-compatible) shell.
                     22: # Written by Paul Eggert <eggert@twinsun.com>,
                     23: # from an idea suggested by Albert Chin-A-Young <china@thewrittenword.com>.
                     24: AC_DEFUN([AC_PROG_SHELL],
                     25:   [AC_MSG_CHECKING([for a POSIX-compliant shell])
                     26:    AC_CACHE_VAL(ac_cv_path_shell,
                     27:      [ac_command='
                     28:         # Test the noclobber option, using the portable POSIX.2 syntax.
                     29:         set -C
                     30:         rm -f conftest.c
                     31:         >conftest.c || exit
                     32:         >|conftest.c || exit
                     33:         !>conftest.c || exit
                     34:         # Test that $(...) works.
                     35:         test "$(expr 3 + 4)" -eq 7 || exit
                     36:       '
                     37:       # Solaris 11 /bin/sh (AT&T Research) 93u 2011-02-08 has a file
                     38:       # descriptor bug that breaks zgrep and is hard to test for
                     39:       # directly.  At some point $(...) is reading a pipe from the
                     40:       # subshell, but the pipe is also open in the parent shell, so
                     41:       # the read deadlocks.  Prefer some other shell if available.
                     42:       ac_maybe_solaris_sh_bug='test "${.sh.version}"'
                     43: 
                     44:       ac_cv_path_shell=no
                     45: 
                     46:       case $SHELL in
                     47:       /*)
                     48:         rm -f conftest.c
                     49:         if ("$SHELL" -c "$ac_command") 2>/dev/null; then
                     50:           "$SHELL" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null ||
                     51:             ac_cv_path_shell=$SHELL
                     52:         fi
                     53:       esac
                     54: 
                     55:       case $ac_cv_path_shell in
                     56:       no)
                     57:         # Prefer shells that are more likely to be installed in the
                     58:         # same place on all hosts of this platform.  Therefore, prefer
                     59:         # shells in /bin and /usr/bin to shells in the installer's
                     60:         # PATH.  Also, loop through PATH first and then through
                     61:         # shells, since less-"nice" shells in /bin and /usr/bin are
                     62:         # more likely to be installed than "nicer" shells elsewhere.
                     63:         ac_break_if_good_shell=:
                     64:         as_save_IFS=$IFS; IFS=:
                     65:         for as_dir in /bin /usr/bin $PATH
                     66:         do
                     67:           IFS=$as_save_IFS
                     68:           case $as_dir in
                     69:           /*)
                     70:             for ac_base in sh bash ksh sh5; do
                     71:               rm -f conftest.c
                     72:               if ("$as_dir/$ac_base" -c "$ac_command") 2>/dev/null; then
                     73:                 if "$as_dir/$ac_base" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null
                     74:                 then
                     75:                   test "$ac_cv_path_shell" = no
                     76:                 else
                     77:                   ac_break_if_good_shell=break
                     78:                   :
                     79:                 fi && ac_cv_path_shell=$as_dir/$ac_base
                     80:                 $ac_break_if_good_shell
                     81:               fi
                     82:             done
                     83:             $ac_break_if_good_shell
                     84:           esac
                     85:         done
                     86:         rm -f conftest.c
                     87:       esac])
                     88:    AC_MSG_RESULT($ac_cv_path_shell)
                     89:    SHELL=$ac_cv_path_shell
                     90:    if test "$SHELL" = no; then
                     91:      SHELL=/bin/sh
                     92:      AC_MSG_WARN([using $SHELL, even though it does not conform to POSIX])
                     93:    fi
                     94:    if "$SHELL" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null; then
                     95:      AC_MSG_WARN([using $SHELL, even though it may have file descriptor bugs])
                     96:    fi
                     97:    AC_SUBST(SHELL)])