configure: use `AC_PROG_EGREP` to find a suitable `grep -E`

On some systems, this is `ggrep -E`.

diff --git a/Makefile.am b/Makefile.am
index abc3c7427a1c69a5becb4fcdda6b56a994254c69..23c55f37ce8a1dbef8709d25c68fdaf29051d05d 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -14,7 +14,7 @@ __force-changelog-generation:
 ChangeLog: __force-changelog-generation
        $(AM_V_GEN)if test -d $(top_srcdir)/.git; then \
                prev=$$(git describe --tags --always --match '[0-9]*' 2> /dev/null) ; \
-               for tag in $$(git tag | grep -E '^[0-9]+(\.[0-9]+){1,}$$' | sort -rn); do \
+               for tag in $$(git tag | $(EGREP) '^[0-9]+(\.[0-9]+){1,}$$' | sort -rn); do \
                        if [ x"$$prev" = x ]; then prev=$$tag ; fi ; \
                        if [ x"$$prev" = x"$$tag" ]; then continue; fi ; \
                        echo "$$prev [$$(git log $$prev -1 --pretty=format:'%ai')]:" ; \

diff --git a/configure.ac b/configure.ac
index 708c2ed375afb01622149feb8adae33e0d7e4441..570031bc8f666f5830a57640c82fcbca5bb6bbda 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -43,6 +43,7 @@ AC_PROG_CXX
 AM_PROG_CC_C_O
 AC_PROG_LIBTOOL
 AC_PROG_LN_S
+AC_PROG_EGREP
 
 # Doxygen
 DX_HTML_FEATURE(ON)