allow grep -E, and remove egrep

index 9fca21cc5f..cb7a367ea0 100644
@@ -162,8 +162,6 @@ For shell scripts specifically (not exhaustive):
 
    - We do not use \{m,n\};
 
-   - We do not use -E;
-
    - We do not use ? or + (which are \{0,1\} and \{1,\}
      respectively in BRE) but that goes without saying as these
      are ERE elements not BRE (note that \? and \+ are not even part

index 9723c2827c..f05ac1fe0b 100755
@@ -201,8 +201,10 @@ test_expect_success 'git branch -M baz bam should succeed when baz is checked ou
 
 test_expect_success 'git branch -M baz bam should add entries to .git/logs/HEAD' '
 	msg="Branch: renamed refs/heads/baz to refs/heads/bam" &&
-	grep " 0\{40\}.*$msg$" .git/logs/HEAD &&
-	grep "^0\{40\}.*$msg$" .git/logs/HEAD
+	zero="00000000" &&
+	zero="$zero$zero$zero$zero$zero" &&
+	grep " $zero.*$msg$" .git/logs/HEAD &&
+	grep "^$zero.*$msg$" .git/logs/HEAD
 '
 
 test_expect_success 'git branch -M should leave orphaned HEAD alone' '

index 22ffe5bcb9..aa3bb2e308 100755
@@ -9,7 +9,7 @@ path_has_fanout() {
 	path=$1 &&
 	fanout=$2 &&
 	after_last_slash=$(($(test_oid hexsz) - $fanout * 2)) &&
-	echo $path | grep -q "^\([0-9a-f]\{2\}/\)\{$fanout\}[0-9a-f]\{$after_last_slash\}$"
+	echo $path | grep -q -E "^([0-9a-f][0-9a-f]/){$fanout}[0-9a-f]{$after_last_slash}$"
 }
 
 touched_one_note_with_fanout() {

index 688b01e3eb..4f5abb5ad2 100755
@@ -1244,9 +1244,9 @@ test_expect_success 'short commit ID collide' '
 		test $colliding_id = "$(git rev-parse HEAD | cut -c 1-4)" &&
 		grep "^pick $colliding_id " \
 			.git/rebase-merge/git-rebase-todo.tmp &&
-		grep "^pick [0-9a-f]\{$hexsz\}" \
+		grep -E "^pick [0-9a-f]{$hexsz}" \
 			.git/rebase-merge/git-rebase-todo &&
-		grep "^pick [0-9a-f]\{$hexsz\}" \
+		grep -E "^pick [0-9a-f]{$hexsz}" \
 			.git/rebase-merge/git-rebase-todo.backup &&
 		git rebase --continue
 	) &&

@@ -1261,7 +1261,7 @@ test_expect_success 'respect core.abbrev' '
 		set_cat_todo_editor &&
 		test_must_fail git rebase -i HEAD~4 >todo-list
 	) &&
-	test 4 = $(grep -c "pick [0-9a-f]\{12,\}" todo-list)
+	test 4 = $(grep -c -E "pick [0-9a-f]{12,}" todo-list)
 '
 
 test_expect_success 'todo count' '

index d7cf85ffea..8f182a3cbf 100755
@@ -234,7 +234,7 @@ test_expect_success 'http-fetch --packfile' '
 		--index-pack-arg=--keep \
 		"$HTTPD_URL"/dumb/repo_pack.git/$p >out &&
 
-	grep "^keep.[0-9a-f]\{16,\}$" out &&
+	grep -E "^keep.[0-9a-f]{16,}$" out &&
 	cut -c6- out >packhash &&
 
 	# Ensure that the expected files are generated

index 5d42a355a8..b33cd4afca 100755
@@ -1001,7 +1001,7 @@ test_expect_success 'part of packfile response provided as URI' '
 	do
 		git verify-pack --object-format=$(test_oid algo) --verbose $idx >out &&
 		{
-			grep "^[0-9a-f]\{16,\} " out || :
+			grep -E "^[0-9a-f]{16,} " out || :
 		} >out.objectlist &&
 		if test_line_count = 1 out.objectlist
 		then

index 33da4d2aba..34115edec3 100755
@@ -232,10 +232,10 @@ then
 	)
 elif test -n "$GIT_PERF_SUBSECTION"
 then
-	egrep "^$GIT_PERF_SUBSECTION\$" "$TEST_RESULTS_DIR"/run_subsections.names >/dev/null ||
+	grep -E "^$GIT_PERF_SUBSECTION\$" "$TEST_RESULTS_DIR"/run_subsections.names >/dev/null ||
 		die "subsection '$GIT_PERF_SUBSECTION' not found in '$GIT_PERF_CONFIG_FILE'"
 
-	egrep "^$GIT_PERF_SUBSECTION\$" "$TEST_RESULTS_DIR"/run_subsections.names | while read -r subsec
+	grep -E "^$GIT_PERF_SUBSECTION\$" "$TEST_RESULTS_DIR"/run_subsections.names | while read -r subsec
 	do
 		(
 			GIT_PERF_SUBSECTION="$subsec"

index 335d3f3211..c69ae41306 100755
@@ -18,7 +18,7 @@ test_expect_success 'checking for a working acl setup' '
 	if setfacl -m d:m:rwx -m u:root:rwx . &&
 	   getfacl . | grep user:root:rwx &&
 	   touch should-have-readable-acl &&
-	   getfacl should-have-readable-acl | egrep "mask::?rw-"
+	   getfacl should-have-readable-acl | grep -E "mask::?rw-"
 	then
 		test_set_prereq SETFACL
 	fi

@@ -34,7 +34,7 @@ check_perms_and_acl () {
 	getfacl "$1" > actual &&
 	grep -q "user:root:rwx" actual &&
 	grep -q "user:${LOGNAME}:rwx" actual &&
-	egrep "mask::?r--" actual > /dev/null 2>&1 &&
+	grep -E "mask::?r--" actual > /dev/null 2>&1 &&
 	grep -q "group::---" actual || false
 }
 

index a1801a8cbd..82bfb2fd2a 100755
@@ -100,7 +100,7 @@ EOF
 
 echo "#!$SHELL_PATH" >fake-editor.sh
 cat >> fake-editor.sh <<\EOF
-egrep -v '^index' "$1" >orig-patch &&
+grep -E -v '^index' "$1" >orig-patch &&
 mv -f patch "$1"
 EOF
 

index ad5c029279..de1da4673d 100755
@@ -1457,7 +1457,7 @@ append_signoff()
 	C=$(git commit-tree HEAD^^{tree} -p HEAD) &&
 	git format-patch --stdout --signoff $C^..$C >append_signoff.patch &&
 	sed -n -e "1,/^---$/p" append_signoff.patch |
-		egrep -n "^Subject|Sign|^$"
+		grep -E -n "^Subject|Sign|^$"
 }
 
 test_expect_success 'signoff: commit with no body' '

@@ -2274,10 +2274,10 @@ test_expect_success 'format-patch --base with --attach' '
 test_expect_success 'format-patch --attach cover-letter only is non-multipart' '
 	test_when_finished "rm -fr patches" &&
 	git format-patch -o patches --cover-letter --attach=mimemime --base=HEAD~ -1 &&
-	! egrep "^--+mimemime" patches/0000*.patch &&
-	egrep "^--+mimemime$" patches/0001*.patch >output &&
+	! grep -E "^--+mimemime" patches/0000*.patch &&
+	grep -E "^--+mimemime$" patches/0001*.patch >output &&
 	test_line_count = 2 output &&
-	egrep "^--+mimemime--$" patches/0001*.patch >output &&
+	grep -E "^--+mimemime--$" patches/0001*.patch >output &&
 	test_line_count = 1 output
 '
 

index 124d47603d..406363381f 100755
@@ -134,7 +134,7 @@ test_expect_success 'island core places core objects first' '
 	    repack -adfi &&
 	git verify-pack -v .git/objects/pack/*.pack |
 	cut -d" " -f1 |
-	egrep "$root|$two" >actual &&
+	grep -E "$root|$two" >actual &&
 	test_cmp expect actual
 '
 

index 56c0dfffea..1746d30cf6 100755
@@ -939,9 +939,9 @@ test_expect_success CASE_INSENSITIVE_FS 'case insensitive+preserving' '
 	# directories and files that we touched.  We may or may not get a
 	# trailing slash on modified directories.
 	#
-	egrep "^event: abc/?$"       ./insensitive.trace &&
-	egrep "^event: abc/def/?$"   ./insensitive.trace &&
-	egrep "^event: abc/def/xyz$" ./insensitive.trace
+	grep -E "^event: abc/?$"       ./insensitive.trace &&
+	grep -E "^event: abc/def/?$"   ./insensitive.trace &&
+	grep -E "^event: abc/def/xyz$" ./insensitive.trace
 '
 
 # The variable "unicode_debug" is defined in the following library

@@ -983,20 +983,20 @@ test_expect_success !UNICODE_COMPOSITION_SENSITIVE 'Unicode nfc/nfd' '
 	then
 		# We should have seen NFC event from OS.
 		# We should not have synthesized an NFD event.
-		egrep    "^event: nfc/c_${utf8_nfc}/?$" ./unicode.trace &&
-		egrep -v "^event: nfc/c_${utf8_nfd}/?$" ./unicode.trace
+		grep -E    "^event: nfc/c_${utf8_nfc}/?$" ./unicode.trace &&
+		grep -E -v "^event: nfc/c_${utf8_nfd}/?$" ./unicode.trace
 	else
 		# We should have seen NFD event from OS.
 		# We should have synthesized an NFC event.
-		egrep "^event: nfc/c_${utf8_nfd}/?$" ./unicode.trace &&
-		egrep "^event: nfc/c_${utf8_nfc}/?$" ./unicode.trace
+		grep -E "^event: nfc/c_${utf8_nfd}/?$" ./unicode.trace &&
+		grep -E "^event: nfc/c_${utf8_nfc}/?$" ./unicode.trace
 	fi &&
 
 	# We assume UNICODE_NFD_PRESERVED.
 	# We should have seen explicit NFD from OS.
 	# We should have synthesized an NFC event.
-	egrep "^event: nfd/d_${utf8_nfd}/?$" ./unicode.trace &&
-	egrep "^event: nfd/d_${utf8_nfc}/?$" ./unicode.trace
+	grep -E "^event: nfd/d_${utf8_nfd}/?$" ./unicode.trace &&
+	grep -E "^event: nfd/d_${utf8_nfc}/?$" ./unicode.trace
 '
 
 test_done

index 937f89ee8c..b7ac4f598a 100755
@@ -35,7 +35,7 @@ test_expect_success '-A with -d option leaves unreachable objects unpacked' '
 	git repack -A -d -l &&
 	# verify objects are packed in repository
 	test 3 = $(git verify-pack -v -- .git/objects/pack/*.idx |
-		   egrep "^($fsha1|$csha1|$tsha1) " |
+		   grep -E "^($fsha1|$csha1|$tsha1) " |
 		   sort | uniq | wc -l) &&
 	git show $fsha1 &&
 	git show $csha1 &&

@@ -49,7 +49,7 @@ test_expect_success '-A with -d option leaves unreachable objects unpacked' '
 	git repack -A -d -l &&
 	# verify objects are retained unpacked
 	test 0 = $(git verify-pack -v -- .git/objects/pack/*.idx |
-		   egrep "^($fsha1|$csha1|$tsha1) " |
+		   grep -E "^($fsha1|$csha1|$tsha1) " |
 		   sort | uniq | wc -l) &&
 	git show $fsha1 &&
 	git show $csha1 &&

index 01c74b8b07..1130ef21b3 100755
@@ -1519,7 +1519,7 @@ test_expect_success $PREREQ 'asks about and fixes 8bit encodings' '
 	grep "do not declare a Content-Transfer-Encoding" stdout &&
 	grep email-using-8bit stdout &&
 	grep "Which 8bit encoding" stdout &&
-	egrep "Content|MIME" msgtxt1 >actual &&
+	grep -E "Content|MIME" msgtxt1 >actual &&
 	test_cmp content-type-decl actual
 '
 

@@ -1530,7 +1530,7 @@ test_expect_success $PREREQ 'sendemail.8bitEncoding works' '
 	git send-email [email protected] [email protected] \
 			--smtp-server="$(pwd)/fake.sendmail" \
 			email-using-8bit >stdout &&
-	egrep "Content|MIME" msgtxt1 >actual &&
+	grep -E "Content|MIME" msgtxt1 >actual &&
 	test_cmp content-type-decl actual
 '
 

@@ -1545,7 +1545,7 @@ test_expect_success $PREREQ 'sendemail.8bitEncoding in .git/config overrides --g
 	git send-email [email protected] [email protected] \
 			--smtp-server="$(pwd)/fake.sendmail" \
 			email-using-8bit >stdout &&
-	egrep "Content|MIME" msgtxt1 >actual &&
+	grep -E "Content|MIME" msgtxt1 >actual &&
 	test_cmp content-type-decl actual
 '
 

@@ -1557,7 +1557,7 @@ test_expect_success $PREREQ '--8bit-encoding overrides sendemail.8bitEncoding' '
 			--smtp-server="$(pwd)/fake.sendmail" \
 			--8bit-encoding=UTF-8 \
 			email-using-8bit >stdout &&
-	egrep "Content|MIME" msgtxt1 >actual &&
+	grep -E "Content|MIME" msgtxt1 >actual &&
 	test_cmp content-type-decl actual
 '
 

index 468767cbf4..2a9838f37f 100755
@@ -216,7 +216,7 @@ test_expect_success 'detect copies' '
 # variable exists, which allows admins to disable the "p4 move" command.
 test_lazy_prereq P4D_HAVE_CONFIGURABLE_RUN_MOVE_ALLOW '
 	p4 configure show run.move.allow >out &&
-	egrep ^run.move.allow: out
+	grep -E ^run.move.allow: out
 '
 
 # If move can be disabled, turn it off and test p4 move handling

index 9779dc0d11..0ca9937de6 100755
@@ -417,8 +417,8 @@ test_expect_success 'cleanup chmod after submit cancel' '
 		! p4 fstat -T action text &&
 		test_path_is_file text+x &&
 		! p4 fstat -T action text+x &&
-		ls -l text | egrep ^-r-- &&
-		ls -l text+x | egrep ^-r-x
+		ls -l text | grep -E ^-r-- &&
+		ls -l text+x | grep -E ^-r-x
 	)
 '
 

index c6479f24eb..527a714500 100644
@@ -897,7 +897,7 @@ test_path_is_symlink () {
 test_dir_is_empty () {
 	test "$#" -ne 1 && BUG "1 param"
 	test_path_is_dir "$1" &&
-	if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')"
+	if test -n "$(ls -a1 "$1" | grep -E -v '^\.\.?$')"
 	then
 		echo "Directory '$1' is not empty, it contains:"
 		ls -la "$1"

index 8689b48589..51afbd7b24 100755
@@ -291,7 +291,7 @@ test_expect_success BSLASHPSPEC "git add 'fo\\[ou\\]bar' ignores foobar" '
 	git reset --hard &&
 	touch fo\[ou\]bar foobar &&
 	git add '\''fo\[ou\]bar'\'' &&
-	git ls-files fo\[ou\]bar | fgrep fo\[ou\]bar &&
+	git ls-files fo\[ou\]bar | grep -F fo\[ou\]bar &&
 	! ( git ls-files foobar | grep foobar )
 '
 

index e18a218952..a00cdba049 100755
@@ -49,7 +49,7 @@ test_expect_success 'result is really identical' '
 test_expect_success 'rewrite bare repository identically' '
 	(git config core.bare true && cd .git &&
 	 git filter-branch branch > filter-output 2>&1 &&
-	! fgrep fatal filter-output)
+	! grep -F fatal filter-output)
 '
 git config core.bare false
 test_expect_success 'result is really identical' '

@@ -506,7 +506,7 @@ test_expect_success 'rewrite repository including refs that point at non-commit
 	git tag -a -m "tag to a tree" treetag $new_tree &&
 	git reset --hard HEAD &&
 	git filter-branch -f -- --all >filter-output 2>&1 &&
-	! fgrep fatal filter-output
+	! grep -F fatal filter-output
 '
 
 test_expect_success 'filter-branch handles ref deletion' '

index f894860867..d8d536269c 100755
@@ -35,7 +35,7 @@ test_expect_success 'SVN-side change outside of .git' '
 		echo b >> a &&
 		svn_cmd commit -m "SVN-side change outside of .git" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change outside of .git"
+		svn_cmd log -v | grep -F "SVN-side change outside of .git"
 	)
 '
 

@@ -59,7 +59,7 @@ test_expect_success 'SVN-side change inside of .git' '
 		svn_cmd add --force .git &&
 		svn_cmd commit -m "SVN-side change inside of .git" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change inside of .git"
+		svn_cmd log -v | grep -F "SVN-side change inside of .git"
 	)
 '
 

@@ -82,7 +82,7 @@ test_expect_success 'SVN-side change in and out of .git' '
 		git commit -m "add a inside an SVN repo" &&
 		svn_cmd commit -m "SVN-side change in and out of .git" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change in and out of .git"
+		svn_cmd log -v | grep -F "SVN-side change in and out of .git"
 	)
 '
 

index 4a77eb9f60..21b5d285d5 100755
@@ -43,7 +43,7 @@ test_expect_success 'init+fetch an SVN repository with ignored www directory' '
 test_expect_success 'verify ignore-paths config saved by clone' '
 	(
 	    cd g &&
-	    git config --get svn-remote.svn.ignore-paths | fgrep "www"
+	    git config --get svn-remote.svn.ignore-paths | grep -F "www"
 	)
 '
 

@@ -53,7 +53,7 @@ test_expect_success 'SVN-side change outside of www' '
 		echo b >> qqq/test_qqq.txt &&
 		svn_cmd commit -m "SVN-side change outside of www" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change outside of www"
+		svn_cmd log -v | grep -F "SVN-side change outside of www"
 	)
 '
 

@@ -85,7 +85,7 @@ test_expect_success 'SVN-side change inside of ignored www' '
 		echo zaq >> www/test_www.txt &&
 		svn_cmd commit -m "SVN-side change inside of www/test_www.txt" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change inside of www/test_www.txt"
+		svn_cmd log -v | grep -F "SVN-side change inside of www/test_www.txt"
 	)
 '
 

@@ -118,7 +118,7 @@ test_expect_success 'SVN-side change in and out of ignored www' '
 		echo ygg >> qqq/test_qqq.txt &&
 		svn_cmd commit -m "SVN-side change in and out of ignored www" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change in and out of ignored www"
+		svn_cmd log -v | grep -F "SVN-side change in and out of ignored www"
 	)
 '
 

index e855904629..b3c9425d55 100755
@@ -43,7 +43,7 @@ test_expect_success 'fetch fails on modified hidden file' '
 	  git svn find-rev refs/remotes/git-svn > ../expect &&
 	  test_must_fail git svn fetch 2> ../errors &&
 	  git svn find-rev refs/remotes/git-svn > ../expect2 ) &&
-	fgrep "not found in commit" errors &&
+	grep -F "not found in commit" errors &&
 	test_cmp expect expect2
 '
 

@@ -59,7 +59,7 @@ test_expect_success 'refetch succeeds not ignoring any files' '
 	( cd g &&
 	  git svn fetch &&
 	  git svn rebase &&
-	  fgrep "mod hidden" hid/hid.txt
+	  grep -F "mod hidden" hid/hid.txt
 	)
 '
 

index 257fc8f2f8..e53bfc02f6 100755
@@ -45,7 +45,7 @@ test_expect_success 'init+fetch an SVN repository with included qqq directory' '
 test_expect_success 'verify include-paths config saved by clone' '
 	(
 	    cd g &&
-	    git config --get svn-remote.svn.include-paths | fgrep "qqq"
+	    git config --get svn-remote.svn.include-paths | grep -F "qqq"
 	)
 '
 

@@ -55,7 +55,7 @@ test_expect_success 'SVN-side change outside of www' '
 		echo b >> qqq/test_qqq.txt &&
 		svn_cmd commit -m "SVN-side change outside of www" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change outside of www"
+		svn_cmd log -v | grep -F "SVN-side change outside of www"
 	)
 '
 

@@ -87,7 +87,7 @@ test_expect_success 'SVN-side change inside of ignored www' '
 		echo zaq >> www/test_www.txt &&
 		svn_cmd commit -m "SVN-side change inside of www/test_www.txt" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change inside of www/test_www.txt"
+		svn_cmd log -v | grep -F "SVN-side change inside of www/test_www.txt"
 	)
 '
 

@@ -120,7 +120,7 @@ test_expect_success 'SVN-side change in and out of included qqq' '
 		echo ygg >> qqq/test_qqq.txt &&
 		svn_cmd commit -m "SVN-side change in and out of ignored www" &&
 		svn_cmd up &&
-		svn_cmd log -v | fgrep "SVN-side change in and out of ignored www"
+		svn_cmd log -v | grep -F "SVN-side change in and out of ignored www"
 	)
 '