tests: Avoid non-portable 'echo -ARG'

POSIX says that backslashes in the arguments to 'echo', as well as
any use of 'echo -n' and 'echo -e', are non-portable; it recommends
people should favor 'printf' instead.  This is definitely true where
we do not control which shell is running (such as in makefile snippets
or in documentation examples).  But even for scripts where we
require bash (and therefore, where echo does what we want by default),
it is still possible to use 'shopt -s xpg_echo' to change bash's
behavior of echo.  And setting a good example never hurts when we are
not sure if a snippet will be copied from a bash-only script to a
general shell script (although I don't change the use of non-portable
\e for ESC when we know the running shell is bash).

Replace 'echo -n "..."' with 'printf %s "..."', and 'echo -e "..."'
with 'printf %b "...\n"', with the optimization that the %s/%b
argument can be omitted if the string being printed is a strict
literal with no '%', '$', or '`' (we could technically also make
this optimization when there are $ or `` substitutions but where
we can prove their results will not be problematic, but proving
that such substitutions are safe makes the patch less trivial
compared to just being consistent).

In the qemu-iotests check script, fix unusual shell quoting
that would result in word-splitting if 'date' outputs a space.

In test 051, take an opportunity to shorten the line.

In test 068, get rid of a pointless second invocation of bash.

CC: qemu-trivial@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170703180950.9895-1-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

5 files changed, 45 insertions, 44 deletions

diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index 26c29de..c8cfc76 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -217,7 +217,7 @@ run_qemu -drive driver=null-co,cache=invalid_value
 # Test 142 checks the direct=on cases
 
 for cache in writeback writethrough unsafe invalid_value; do
-    echo -e "info block\ninfo block file\ninfo block backing\ninfo block backing-file" | \
+    printf "info block %s\n" '' file backing backing-file | \
     run_qemu -drive file="$TEST_IMG",cache=$cache,backing.file.filename="$TEST_IMG.base",backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=$device_id -nodefaults
 done
 
@@ -325,8 +325,9 @@ echo "qemu-io $device_id \"write -P 0x22 0 4k\"" | run_qemu -drive file="$TEST_I
 
 $QEMU_IO -c "read -P 0x22 0 4k" "$TEST_IMG" | _filter_qemu_io
 
-echo -e "qemu-io $device_id \"write -P 0x33 0 4k\"\ncommit $device_id" | run_qemu -drive file="$TEST_IMG",snapshot=on,if=none,id=$device_id\
-                                                                       | _filter_qemu_io
+printf %b "qemu-io $device_id \"write -P 0x33 0 4k\"\ncommit $device_id\n" |
+    run_qemu -drive file="$TEST_IMG",snapshot=on,if=none,id=$device_id |
+    _filter_qemu_io
 
 $QEMU_IO -c "read -P 0x33 0 4k" "$TEST_IMG" | _filter_qemu_io
 
diff --git a/tests/qemu-iotests/068 b/tests/qemu-iotests/068
index 3801b65..cfa0f2a 100755
--- a/tests/qemu-iotests/068
+++ b/tests/qemu-iotests/068
@@ -76,7 +76,7 @@ for extra_args in \
     _make_test_img $IMG_SIZE
 
     # Give qemu some time to boot before saving the VM state
-    bash -c 'sleep 1; echo -e "savevm 0\nquit"' | _qemu $extra_args
+    { sleep 1; printf "savevm 0\nquit\n"; } | _qemu $extra_args
     # Now try to continue from that VM state (this should just work)
     echo quit | _qemu $extra_args -loadvm 0
 done
diff --git a/tests/qemu-iotests/142 b/tests/qemu-iotests/142
index 9a5b713..1639c83 100755
--- a/tests/qemu-iotests/142
+++ b/tests/qemu-iotests/142
@@ -94,36 +94,36 @@ function check_cache_all()
     # cache.direct is supposed to be inherited by both bs->file and
     # bs->backing
 
-    echo -e "cache.direct=on on none0"
+    printf "cache.direct=on on none0\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
-    echo -e "\ncache.direct=on on file"
+    printf "\ncache.direct=on on file\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
-    echo -e "\ncache.direct=on on backing"
+    printf "\ncache.direct=on on backing\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
-    echo -e "\ncache.direct=on on backing-file"
+    printf "\ncache.direct=on on backing-file\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
 
     # cache.writeback is supposed to be inherited by bs->backing; bs->file
     # always gets cache.writeback=on
 
-    echo -e "\n\ncache.writeback=off on none0"
+    printf "\n\ncache.writeback=off on none0\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.writeback=off on file"
+    printf "\ncache.writeback=off on file\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.writeback=off | grep -e "doesn't" -e "does not"
-    echo -e "\ncache.writeback=off on backing"
+    printf "\ncache.writeback=off on backing\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.writeback=off | grep -e "doesn't" -e "does not"
-    echo -e "\ncache.writeback=off on backing-file"
+    printf "\ncache.writeback=off on backing-file\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.writeback=off | grep -e "doesn't" -e "does not"
 
     # cache.no-flush is supposed to be inherited by both bs->file and bs->backing
 
-    echo -e "\n\ncache.no-flush=on on none0"
+    printf "\n\ncache.no-flush=on on none0\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.no-flush=on on file"
+    printf "\ncache.no-flush=on on file\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.no-flush=on on backing"
+    printf "\ncache.no-flush=on on backing\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.no-flush=on on backing-file"
+    printf "\ncache.no-flush=on on backing-file\n"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
 }
 
@@ -236,35 +236,35 @@ function check_cache_all_separate()
 {
     # Check cache.direct
 
-    echo -e "cache.direct=on on blk"
+    printf "cache.direct=on on blk\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.direct=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.direct=on on file"
+    printf "\ncache.direct=on on file\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.direct=on -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.direct=on on backing"
+    printf "\ncache.direct=on on backing\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.direct=on -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.direct=on on backing-file"
+    printf "\ncache.direct=on on backing-file\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.direct=on -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
 
     # Check cache.writeback
 
-    echo -e "\n\ncache.writeback=off on blk"
+    printf "\n\ncache.writeback=off on blk\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.writeback=off on file"
+    printf "\ncache.writeback=off on file\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.writeback=off -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.writeback=off on backing"
+    printf "\ncache.writeback=off on backing\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.writeback=off -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.writeback=off on backing-file"
+    printf "\ncache.writeback=off on backing-file\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.writeback=off -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
 
     # Check cache.no-flush
 
-    echo -e "\n\ncache.no-flush=on on blk"
+    printf "\n\ncache.no-flush=on on blk\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.no-flush=on on file"
+    printf "\ncache.no-flush=on on file\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.no-flush=on -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.no-flush=on on backing"
+    printf "\ncache.no-flush=on on backing\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.no-flush=on -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
-    echo -e "\ncache.no-flush=on on backing-file"
+    printf "\ncache.no-flush=on on backing-file\n"
     echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.no-flush=on -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
 }
 
diff --git a/tests/qemu-iotests/171 b/tests/qemu-iotests/171
index 257be10..bcfaaf1 100755
--- a/tests/qemu-iotests/171
+++ b/tests/qemu-iotests/171
@@ -45,15 +45,15 @@ _supported_os Linux
 
 # Create JSON with options
 img_json() {
-    echo -n 'json:{"driver":"raw", '
-    echo -n "\"offset\":\"$img_offset\", "
+    printf %s 'json:{"driver":"raw", '
+    printf %s "\"offset\":\"$img_offset\", "
     if [ "$img_size" -ne -1 ] ; then
-        echo -n "\"size\":\"$img_size\", "
+        printf %s "\"size\":\"$img_size\", "
     fi
-    echo -n '"file": {'
-    echo -n    '"driver":"file", '
-    echo -n    "\"filename\":\"$TEST_IMG\" "
-    echo -n "} }"
+    printf %s '"file": {'
+    printf %s   '"driver":"file", '
+    printf %s   "\"filename\":\"$TEST_IMG\" "
+    printf %s "} }"
 }
 
 do_general_test() {
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 4b1c674..9ded37c 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -141,7 +141,7 @@ _wallclock()
 _timestamp()
 {
     now=`date "+%T"`
-    echo -n " [$now]"
+    printf %s " [$now]"
 }
 
 _wrapup()
@@ -255,7 +255,7 @@ seq="check"
 for seq in $list
 do
     err=false
-    echo -n "$seq"
+    printf %s "$seq"
     if [ -n "$TESTS_REMAINING_LOG" ] ; then
         sed -e "s/$seq//" -e 's/  / /' -e 's/^ *//' $TESTS_REMAINING_LOG > $TESTS_REMAINING_LOG.tmp
         mv $TESTS_REMAINING_LOG.tmp $TESTS_REMAINING_LOG
@@ -281,9 +281,9 @@ do
         rm -f $seq.out.bad
         lasttime=`sed -n -e "/^$seq /s/.* //p" <$TIMESTAMP_FILE`
         if [ "X$lasttime" != X ]; then
-                echo -n " ${lasttime}s ..."
+                printf %s " ${lasttime}s ..."
         else
-                echo -n "        "        # prettier output with timestamps.
+                printf "        "        # prettier output with timestamps.
         fi
         rm -f core $seq.notrun
 
@@ -291,7 +291,7 @@ do
         echo "$seq" > "${TEST_DIR}"/check.sts
 
         start=`_wallclock`
-        $timestamp && echo -n "        ["`date "+%T"`"]"
+        $timestamp && printf %s "        [$(date "+%T")]"
 
         if [ "$(head -n 1 "$source_iotests/$seq")" == "#!/usr/bin/env python" ]; then
             run_command="$PYTHON $seq"
@@ -314,21 +314,21 @@ do
 
         if [ -f core ]
         then
-            echo -n " [dumped core]"
+            printf " [dumped core]"
             mv core $seq.core
             err=true
         fi
 
         if [ -f $seq.notrun ]
         then
-            $timestamp || echo -n " [not run] "
-            $timestamp && echo " [not run]" && echo -n "        $seq -- "
+            $timestamp || printf " [not run] "
+            $timestamp && echo " [not run]" && printf %s "        $seq -- "
             cat $seq.notrun
             notrun="$notrun $seq"
         else
             if [ $sts -ne 0 ]
             then
-                echo -n " [failed, exit status $sts]"
+                printf %s " [failed, exit status $sts]"
                 err=true
             fi