tests: use "compare exp out", not "compare out exp"

Likewise, when an empty file is expected, use "compare /dev/null out",
not "compare out /dev/null". I.e., specify the expected/desired contents
via the first file name.  Prompted by a suggestion from Bruno Haible
in http://thread.gmane.org/gmane.comp.gnu.grep.bugs/4020/focus=29154

Run these commands:

    git grep -l -E 'compare [^ ]+ exp' \
      |xargs perl -pi -e 's/(compare) (\S+) (exp\S*)/$1 $3 $2/'
    git grep -l -E 'compare [^ ]+ /dev/null' \
      |xargs perl -pi -e 's/(compare) (\S+) (\/dev\/null)/$1 $3 $2/'

* tests/chgrp/no-x: As above.
* tests/chmod/no-x: Likewise.
* tests/chmod/silent: Likewise.
* tests/chmod/thru-dangling: Likewise.
* tests/chown/basic: Likewise.
* tests/chown/deref: Likewise.
* tests/chown/preserve-root: Likewise.
* tests/cp/abuse: Likewise.
* tests/cp/backup-is-src: Likewise.
* tests/cp/cp-a-selinux: Likewise.
* tests/cp/cp-mv-enotsup-xattr: Likewise.
* tests/cp/fail-perm: Likewise.
* tests/cp/into-self: Likewise.
* tests/cp/proc-zero-len: Likewise.
* tests/cp/src-base-dot: Likewise.
* tests/cp/thru-dangling: Likewise.
* tests/dd/reblock: Likewise.
* tests/dd/unblock-sync: Likewise.
* tests/du/2g: Likewise.
* tests/du/8gb: Likewise.
* tests/du/basic: Likewise.
* tests/du/bigtime: Likewise.
* tests/du/deref-args: Likewise.
* tests/du/exclude: Likewise.
* tests/du/files0-from-dir: Likewise.
* tests/du/hard-link: Likewise.
* tests/du/inacc-dest: Likewise.
* tests/du/inacc-dir: Likewise.
* tests/du/long-sloop: Likewise.
* tests/du/max-depth: Likewise.
* tests/du/move-dir-while-traversing: Likewise.
* tests/du/no-deref: Likewise.
* tests/du/no-x: Likewise.
* tests/du/one-file-system: Likewise.
* tests/du/slash: Likewise.
* tests/du/trailing-slash: Likewise.
* tests/install/strip-program: Likewise.
* tests/ln/hard-backup: Likewise.
* tests/ls/block-size: Likewise.
* tests/ls/color-clear-to-eol: Likewise.
* tests/ls/color-dtype-dir: Likewise.
* tests/ls/color-norm: Likewise.
* tests/ls/dangle: Likewise.
* tests/ls/dired: Likewise.
* tests/ls/file-type: Likewise.
* tests/ls/follow-slink: Likewise.
* tests/ls/infloop: Likewise.
* tests/ls/m-option: Likewise.
* tests/ls/no-arg: Likewise.
* tests/ls/recursive: Likewise.
* tests/ls/rt-1: Likewise.
* tests/ls/stat-dtype: Likewise.
* tests/ls/stat-failed: Likewise.
* tests/ls/stat-free-symlinks: Likewise.
* tests/ls/x-option: Likewise.
* tests/misc/arch: Likewise.
* tests/misc/cat-buf: Likewise.
* tests/misc/cat-proc: Likewise.
* tests/misc/chcon: Likewise.
* tests/misc/csplit: Likewise.
* tests/misc/df-P: Likewise.
* tests/misc/fmt-long-line: Likewise.
* tests/misc/groups-dash: Likewise.
* tests/misc/groups-version: Likewise.
* tests/misc/head-pos: Likewise.
* tests/misc/nl: Likewise.
* tests/misc/od-N: Likewise.
* tests/misc/od-multiple-t: Likewise.
* tests/misc/od-x8: Likewise.
* tests/misc/printf: Likewise.
* tests/misc/printf-hex: Likewise.
* tests/misc/pwd-option: Likewise.
* tests/misc/readlink-fp-loop: Likewise.
* tests/misc/runcon-no-reorder: Likewise.
* tests/misc/seq-long-double: Likewise.
* tests/misc/sort-NaN-infloop: Likewise.
* tests/misc/sort-benchmark-random: Likewise.
* tests/misc/sort-debug-keys: Likewise.
* tests/misc/sort-float: Likewise.
* tests/misc/sort-merge-fdlimit: Likewise.
* tests/misc/sort-unique-segv: Likewise.
* tests/misc/stat-hyphen: Likewise.
* tests/misc/stat-slash: Likewise.
* tests/misc/stdbuf: Likewise.
* tests/misc/sum-sysv: Likewise.
* tests/misc/tac-2-nonseekable: Likewise.
* tests/misc/tac-continue: Likewise.
* tests/misc/tr-case-class: Likewise.
* tests/misc/truncate-fail-diag: Likewise.
* tests/misc/wc-files0: Likewise.
* tests/mkdir/selinux: Likewise.
* tests/mv/backup-dir: Likewise.
* tests/mv/backup-is-src: Likewise.
* tests/mv/diag: Likewise.
* tests/mv/dir2dir: Likewise.
* tests/mv/dup-source: Likewise.
* tests/mv/force: Likewise.
* tests/mv/hard-verbose: Likewise.
* tests/mv/i-link-no: Likewise.
* tests/mv/into-self: Likewise.
* tests/mv/into-self-2: Likewise.
* tests/mv/into-self-3: Likewise.
* tests/mv/mv-special-1: Likewise.
* tests/mv/part-fail: Likewise.
* tests/mv/perm-1: Likewise.
* tests/mv/sticky-to-xpart: Likewise.
* tests/mv/trailing-slash: Likewise.
* tests/rm/rm1: Likewise.
* tests/rm/rm2: Likewise.
* tests/rm/cycle: Likewise.
* tests/rm/dir-no-w: Likewise.
* tests/rm/dir-nonrecur: Likewise.
* tests/rm/fail-2eperm: Likewise.
* tests/rm/fail-eacces: Likewise.
* tests/rm/i-never: Likewise.
* tests/rm/inaccessible: Likewise.
* tests/rm/interactive-always: Likewise.
* tests/rm/interactive-once: Likewise.
* tests/rm/isatty: Likewise.
* tests/rm/one-file-system: Likewise.
* tests/rm/rm3: Likewise.
* tests/rm/rm5: Likewise.
* tests/rm/unread2: Likewise.
* tests/rm/v-slash: Likewise.
* tests/sample-test: Likewise.
* tests/split/b-chunk: Likewise.
* tests/split/fail: Likewise.
* tests/split/l-chunk: Likewise.
* tests/split/lines: Likewise.
* tests/split/r-chunk: Likewise.
* tests/split/suffix-length: Likewise.
* tests/tail-2/big-4gb: Likewise.
* tests/tail-2/follow-name: Likewise.
* tests/tail-2/follow-stdin: Likewise.
* tests/tail-2/pipe-f: Likewise.
* tests/tail-2/pipe-f2: Likewise.
* tests/tail-2/start-middle: Likewise.
* tests/touch/60-seconds: Likewise.
* tests/touch/fail-diag: Likewise.
* tests/touch/not-owner: Likewise.
* tests/touch/relative: Likewise.

9 files changed, 12 insertions, 12 deletions

diff --git a/tests/cp/abuse b/tests/cp/abuse
index 43b7df0d9..1573ed5b0 100755
--- a/tests/cp/abuse
+++ b/tests/cp/abuse
@@ -34,7 +34,7 @@ for i in dangling-dest existing-dest; do
 
   cp -dR a/1 b/1 c 2> out && fail=1
 
-  compare out exp || fail=1
+  compare exp out || fail=1
 
   # When the destination is a dangling symlink,
   # ensure that cp does not create it.
diff --git a/tests/cp/backup-is-src b/tests/cp/backup-is-src
index bb6478940..9547c4e7e 100755
--- a/tests/cp/backup-is-src
+++ b/tests/cp/backup-is-src
@@ -31,6 +31,6 @@ cat > exp <<\EOF
 XXX: backing up `a' would destroy source;  `a~' not copied
 EOF
 
-compare out2 exp || fail=1
+compare exp out2 || fail=1
 
 Exit $fail
diff --git a/tests/cp/cp-a-selinux b/tests/cp/cp-a-selinux
index 0f9c14938..7ef24d801 100755
--- a/tests/cp/cp-a-selinux
+++ b/tests/cp/cp-a-selinux
@@ -100,7 +100,7 @@ cp --preserve=context f g 2> out && fail=1
 test -s g && fail=1
 sed "s/ .g' to .*//" out > k
 mv k out
-compare out exp || fail=1
+compare exp out || fail=1
 
 rm -f g
 echo > g
@@ -110,6 +110,6 @@ cp -a --preserve=context f g 2> out2 && fail=1
 test -s g && fail=1
 sed "s/ .g' to .*//" out2 > k
 mv k out2
-compare out2 exp || fail=1
+compare exp out2 || fail=1
 
 Exit $fail
diff --git a/tests/cp/cp-mv-enotsup-xattr b/tests/cp/cp-mv-enotsup-xattr
index 32798d2fc..f30358136 100755
--- a/tests/cp/cp-mv-enotsup-xattr
+++ b/tests/cp/cp-mv-enotsup-xattr
@@ -98,7 +98,7 @@ cp: cannot preserve extended attributes, cp is built without xattr support
 EOF
 fi
 
-compare err exp     || fail=1
+compare exp err     || fail=1
 
 rm -f err noxattr/a
 
diff --git a/tests/cp/fail-perm b/tests/cp/fail-perm
index 404c83e39..d05189785 100755
--- a/tests/cp/fail-perm
+++ b/tests/cp/fail-perm
@@ -47,11 +47,11 @@ cp F symlink 2> out && fail=1
 #   ...: The file access permissions do not allow the specified action.
 # to the expected one:
 sed 's/: The file access permissions.*/: Permission denied/'<out>o1;mv o1 out
-compare out exp || fail=1
+compare exp out || fail=1
 
 cp --target-directory=symlink F 2> out && fail=1
 sed 's/: The file access permissions.*/: Permission denied/'<out>o1;mv o1 out
-compare out exp || fail=1
+compare exp out || fail=1
 
 chmod 700 D
 
diff --git a/tests/cp/into-self b/tests/cp/into-self
index deb5a5325..91c3a5a85 100755
--- a/tests/cp/into-self
+++ b/tests/cp/into-self
@@ -52,6 +52,6 @@ cp: cannot copy a directory, `dir', into itself, `dir/dir'
 EOF
 #'
 
-compare out exp || fail=1
+compare exp out || fail=1
 
 Exit $fail
diff --git a/tests/cp/proc-zero-len b/tests/cp/proc-zero-len
index 53abc43f9..cc6fd0fbc 100755
--- a/tests/cp/proc-zero-len
+++ b/tests/cp/proc-zero-len
@@ -35,6 +35,6 @@ cp $f exp || fail=1
 test -s out && { rm -f out; echo nonempty > out; }
 test -s exp && { rm -f exp; echo nonempty > exp; }
 
-compare out exp || fail=1
+compare exp out || fail=1
 
 Exit $fail
diff --git a/tests/cp/src-base-dot b/tests/cp/src-base-dot
index 069c1935c..4ec39a873 100755
--- a/tests/cp/src-base-dot
+++ b/tests/cp/src-base-dot
@@ -27,6 +27,6 @@ cp --verbose -ab ../x/. . > out 2>&1 || fail=1
 cat <<\EOF > exp || fail=1
 EOF
 
-compare out exp || fail=1
+compare exp out || fail=1
 
 Exit $fail
diff --git a/tests/cp/thru-dangling b/tests/cp/thru-dangling
index 62f111587..1c5c12d4c 100755
--- a/tests/cp/thru-dangling
+++ b/tests/cp/thru-dangling
@@ -29,13 +29,13 @@ echo "cp: not writing through dangling symlink \`dangle'" \
 # Starting with 6.9.90, this usage fails, by default:
 cp f dangle > err 2>&1 && fail=1
 
-compare err exp-err || fail=1
+compare exp-err err || fail=1
 test -f no-such && fail=1
 
 # But you can set POSIXLY_CORRECT to get the historical behavior.
 env POSIXLY_CORRECT=1 cp f dangle > out 2>&1 || fail=1
 cat no-such >> out || fail=1
 
-compare out exp || fail=1
+compare exp out || fail=1
 
 Exit $fail