# _AC_PATH_PROG_FEATURE_CHECK(VARIABLE, PROGNAME-LIST, FEATURE-TEST, [PATH])

# --------------------------------------------------------------------------

# FEATURE-TEST is called repeatedly with $ac_path_VARIABLE set to the

# name of a program in PROGNAME-LIST found in PATH. FEATURE-TEST must set

# $ac_cv_path_VARIABLE to the path of an acceptable program, or else

# _AC_PATH_PROG_FEATURE_CHECK will report that no acceptable program

# was found, and abort. If a suitable $ac_path_VARIABLE is found in the

# FEATURE-TEST macro, it can set $ac_path_VARIABLE_found=':' to accept

# that value without any further checks.

m4_define([_AC_PATH_PROG_FEATURE_CHECK],

[# Extract the first word of "$2" to use in msg output

if test -z "$$1"; then

set dummy $2; ac_prog_name=$[2]

AC_CACHE_VAL([ac_cv_path_$1],

[ac_path_$1_found=false

# Loop through the user's path and test for each of PROGNAME-LIST

_AS_PATH_WALK([$4],

[for ac_prog in $2; do

for ac_exec_ext in '' $ac_executable_extensions; do

ac_path_$1="$as_dir/$ac_prog$ac_exec_ext"

AS_EXECUTABLE_P(["$ac_path_$1"]) || continue

$3

$ac_path_$1_found && break 3

done

done

])

])

$1="$ac_cv_path_$1"

if test -z "$$1"; then

AC_MSG_ERROR([no acceptable $ac_prog_name could be found in dnl

m4_default([$4], [\$PATH])])

fi

AC_SUBST([$1])

else

ac_cv_path_$1=$$1

fi

])

# _AC_FEATURE_CHECK_LENGTH(PROGPATH, CACHE-VAR, CHECK-CMD, [MATCH-STRING])

# ------------------------------------------------------------------------

# For use as the FEATURE-TEST argument to _AC_PATH_PROG_FEATURE_TEST.

# On each iteration run CHECK-CMD on an input file, storing the value

# of PROGPATH in CACHE-VAR if the CHECK-CMD succeeds. The input file

# is always one line, starting with only 10 characters, and doubling

# in length at each iteration until approx 10000 characters or the

# feature check succeeds. The feature check is called at each

# iteration by appending (optionally, MATCH-STRING and) a newline

# to the file, and using the result as input to CHECK-CMD.

m4_define([_AC_FEATURE_CHECK_LENGTH],

[# Check for GNU $1 and select it if it is found.

_AC_PATH_PROG_FLAVOR_GNU([$$1],

[$2="$$1" $1_found=:],

[ac_count=0

echo $ECHO_N "0123456789$ECHO_C" >"conftest.in"

while :

do

cat "conftest.in" "conftest.in" >"conftest.tmp"

mv "conftest.tmp" "conftest.in"

cp "conftest.in" "conftest.nl"

echo '$4' >> "conftest.nl"

$3 < "conftest.nl" >"conftest.out" 2>/dev/null || break

diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break

ac_count=`expr $ac_count + 1`

if test $ac_count -gt ${$1_max-0}; then

# Best one so far, save it but keep looking for a better one

$2="$$1"

dnl # Using $1_max so that each tool feature checked gets its

dnl # own variable. Don't reset it otherwise the implied search

dnl # for best performing tool in a list breaks down.

$1_max=$ac_count

fi

# 10*(2^10) chars as input seems more than enough

test $ac_count -gt 10 && break

done

rm -f conftest.in conftest.tmp conftest.nl conftest.out])

])

# _AC_PATH_PROG_FLAVOR_GNU(PROGRAM-PATH, IF-SUCCESS, [IF-FAILURE])

# ----------------------------------------------------------------

m4_define([_AC_PATH_PROG_FLAVOR_GNU],

[# Check for GNU $1

case `"$1" --version 2>&1` in

*GNU*)

$2;;

m4_ifval([$3],

[*)

$3;;

])esac

])# _AC_PATH_PROG_FLAVOR_GNU

# AC_PROG_SED

# -----------

# Check for a fully functional sed program that truncates

# as few characters as possible. Prefer GNU sed if found.

AC_DEFUN([AC_PROG_SED],

[AC_CACHE_CHECK([for a sed that does not truncate output], ac_cv_path_SED,

[dnl ac_script should not contain more than 99 commands (for HP-UX sed),

dnl but more than about 7000 bytes, to catch a limit in Solaris 8 /usr/ucb/sed.

ac_script=s/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb/

for ac_i in 1 2 3 4 5 6 7; do

ac_script="$ac_script$as_nl$ac_script"

done

echo "$ac_script" | sed 99q >conftest.sed

$as_unset ac_script || ac_script=

_AC_PATH_PROG_FEATURE_CHECK(SED, [sed gsed],

[_AC_FEATURE_CHECK_LENGTH([ac_path_SED], [ac_cv_path_SED],

["$ac_path_SED" -f conftest.sed])])])

SED="$ac_cv_path_SED"

AC_SUBST([SED])dnl

rm -f conftest.sed

])# AC_PROG_SED