Fix shellcheck v0.4.6 warnings

Resolve new warnings reported after upgrading to shellcheck
version 0.4.6.  This patch contains no functional changes.

* egrep is non-standard and deprecated. Use grep -E instead. [SC2196]
* Check exit code directly with e.g. 'if mycmd;', not indirectly
  with $?.  [SC2181]  Suppressed.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes openzfs#7040

cmd/zed/zed.d/zed-functions.sh

@@ -397,7 +397,7 @@ zed_rate_limit()
 
     zed_lock "${lockfile}" "${lockfile_fd}"
     time_now="$(date +%s)"
-    time_prev="$(egrep "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \
+    time_prev="$(grep -E "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \
         | tail -1 | cut -d\; -f1)"
 
     if [ -n "${time_prev}" ] \
@@ -406,7 +406,7 @@ zed_rate_limit()
     else
         umask_bak="$(umask)"
         umask 077
-        egrep -v "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \
+        grep -E -v "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \
             > "${statefile}.$$"
         echo "${time_now};${tag}" >> "${statefile}.$$"
         mv -f "${statefile}.$$" "${statefile}"

scripts/commitcheck.sh

@@ -19,7 +19,7 @@ function test_url()
 function check_tagged_line()
 {
     regex='^\s*'"$1"':\s[[:print:]]+\s<[[:graph:]]+>$'
-    foundline=$(git log -n 1 "$REF" | egrep -m 1 "$regex")
+    foundline=$(git log -n 1 "$REF" | grep -E -m 1 "$regex")
     if [ -z "$foundline" ]; then
         echo "error: missing \"$1\""
         return 1
@@ -51,7 +51,7 @@ function new_change_commit()
     error=0
 
     # subject is not longer than 50 characters
-    long_subject=$(git log -n 1 --pretty=%s "$REF" | egrep -m 1 '.{51}')
+    long_subject=$(git log -n 1 --pretty=%s "$REF" | grep -E -m 1 '.{51}')
     if [ -n "$long_subject" ]; then
         echo "error: commit subject over 50 characters"
         error=1
@@ -63,7 +63,7 @@ function new_change_commit()
     fi
 
     # ensure that no lines in the body of the commit are over 72 characters
-    body=$(git log -n 1 --pretty=%b "$REF" | egrep -m 1 '.{73}')
+    body=$(git log -n 1 --pretty=%b "$REF" | grep -E -m 1 '.{73}')
     if [ -n "$body" ]; then
         echo "error: commit message body contains line over 72 characters"
         error=1
@@ -75,7 +75,7 @@ function new_change_commit()
 function is_openzfs_port()
 {
     # subject starts with OpenZFS means it's an openzfs port
-    subject=$(git log -n 1 --pretty=%s "$REF" | egrep -m 1 '^OpenZFS')
+    subject=$(git log -n 1 --pretty=%s "$REF" | grep -E -m 1 '^OpenZFS')
     if [ -n "$subject" ]; then
         return 0
     fi
@@ -86,7 +86,7 @@ function is_openzfs_port()
 function openzfs_port_commit()
 {
     # subject starts with OpenZFS dddd
-    subject=$(git log -n 1 --pretty=%s "$REF" | egrep -m 1 '^OpenZFS [[:digit:]]+ - ')
+    subject=$(git log -n 1 --pretty=%s "$REF" | grep -E -m 1 '^OpenZFS [[:digit:]]+ - ')
     if [ -z "$subject" ]; then
         echo "OpenZFS patch ports must have a summary that starts with \"OpenZFS dddd - \""
         error=1

scripts/zloop.sh

@@ -70,12 +70,12 @@ function or_die
 
 # core file helpers
 origcorepattern="$(cat /proc/sys/kernel/core_pattern)"
-coreglob="$(egrep -o '^([^|%[:space:]]*)' /proc/sys/kernel/core_pattern)*"
+coreglob="$(grep -E -o '^([^|%[:space:]]*)' /proc/sys/kernel/core_pattern)*"
 
 if [[ $coreglob = "*" ]]; then
         echo "Setting core file pattern..."
         echo "core" > /proc/sys/kernel/core_pattern
-        coreglob="$(egrep -o '^([^|%[:space:]]*)' \
+        coreglob="$(grep -E -o '^([^|%[:space:]]*)' \
             /proc/sys/kernel/core_pattern)*"
 fi
 
@@ -235,7 +235,7 @@ while [[ $timeout -eq 0 ]] || [[ $curtime -le $((starttime + timeout)) ]]; do
 	echo "$desc" >>ztest.out
 	$cmd >>ztest.out 2>&1
 	ztrc=$?
-	egrep '===|WARNING' ztest.out >>ztest.history
+	grep -E '===|WARNING' ztest.out >>ztest.history
 	$ZDB -U "$workdir/zpool.cache" -DD ztest >>ztest.ddt
 
 	store_core

tests/zfs-tests/tests/functional/acl/acl_common.kshlib

@@ -410,7 +410,7 @@ function get_xattr #<obj>
 	fi
 
 	for xattr in `runat $obj ls | \
-		/usr/xpg4/bin/egrep -v -e SUNWattr_ro -e SUNWattr_rw` ; do
+		grep -E -v -e SUNWattr_ro -e SUNWattr_rw` ; do
 		runat $obj sum $xattr
 	done
 }