[PATCH] tests/init.sh: new file to be used via most *.sh tests

[Jim Meyering]

I've pushed tests/init.sh, as yet unused.

Obviously, this is just a proposal.
I want to use something like this for each of the tests I own,
because it makes it so easy to avoid conflicts: each test is run
in its own directory, and there's no need to clean up afterwards,
because that happens automatically.

Why bother with mktemp?
Because in an alternate version, there was a way to specify
that you wanted the test to be run in some *other* directory.
In that case, (i.e., if you chose /tmp), you would require
a safe directory name.  Additionally, having a random component
in the name allows you to run more than one "make check" in parallel,
though I'm not sure that's useful.  However, it is useful to have
a different name each time, for when you arrange not to remove
the temporary file: no need to rename each time.

I'll post some examples of using this new framework later today.


>From ef77cd53d352251ed2bc7995ac6951f29f091bad Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Wed, 25 Nov 2009 14:40:31 +0100
Subject: [PATCH] tests/init.sh: new file to be used via most *.sh tests

* tests/init.sh: New file.
---
 ChangeLog     |    5 ++
 tests/init.sh |  216 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 221 insertions(+), 0 deletions(-)
 create mode 100644 tests/init.sh

diff --git a/ChangeLog b/ChangeLog
index 2b4cf53..c0ce45b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-11-25  Jim Meyering  <address@hidden>
+
+       tests/init.sh: new file to be used via most *.sh tests
+       * tests/init.sh: New file.
+
 2009-11-25  Eric Blake  <address@hidden>

        utimens: work around older Linux failure with symlinks
diff --git a/tests/init.sh b/tests/init.sh
new file mode 100644
index 0000000..7d4879f
--- /dev/null
+++ b/tests/init.sh
@@ -0,0 +1,216 @@
+# source this file; set up for tests
+
+# Copyright (C) 2009 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# We use a trap below for cleanup.  This requires us to go through
+# hoops to get the right exit status transported through the handler.
+# So use `Exit STATUS' instead of `exit STATUS' inside of the tests.
+# Turn off errexit here so that we don't trip the bug with OSF1/Tru64
+# sh inside this function.
+Exit () { set +e; (exit $1); exit $1; }
+
+fail_() { echo "$ME_: failed test: $@" 1>&2; Exit 1; }
+skip_() { echo "$ME_: skipped test: $@" 1>&2; Exit 77; }
+
+# This is a stub function that is run upon trap (upon regular exit and
+# interrupt).  Override it with a per-test function, e.g., to unmount
+# a partition, or to undo any other global state changes.
+cleanup_() { :; }
+
+if ( diff --version < /dev/null 2>&1 | grep GNU ) 2>&1 > /dev/null; then
+  compare() { diff -u "$@"; }
+elif ( cmp --version < /dev/null 2>&1 | grep GNU ) 2>&1 > /dev/null; then
+  compare() { cmp -s "$@"; }
+else
+  compare() { cmp "$@"; }
+fi
+
+# An arbitrary prefix to help distinguish test directories.
+testdir_prefix_() { printf gt; }
+
+# Run the user-overridable cleanup_ function, remove the temporary
+# directory and exit with the incoming value of $?.
+remove_tmp_()
+{
+  __st=$?
+  cleanup_
+  # cd out of the directory we're about to remove
+  cd "$initial_cwd_" || cd / || cd /tmp
+  chmod -R u+rwx "$test_dir_"
+  # If removal fails and exit status was to be 0, then change it to 1.
+  rm -rf "$test_dir_" || { test $__st = 0 && __st=1; }
+  exit $__st
+}
+
+setup_()
+{
+  test "$VERBOSE" = yes && set -x
+
+  # Honor one or more --set-path=. options (i.e., or --set-path=../src).
+  # Use this option to prepend to PATH an absolute name for the
+  # specified, possibly-relative, directory.
+  while test $# != 0; do
+    case $1 in
+      --set-path=*)
+        path_dir_=${1#--set-path=}
+        test -z "$path_dir_" && fail_ "missing argument to --set-path="
+        abs_path_dir_=`cd "$path_dir_" && echo "$PWD" || exit 1` \
+            || fail_ "invalid path dir: $path_dir"
+        PATH="$abs_path_dir_:$PATH"
+        export PATH
+        shift
+        ;;
+      *) fail_ "unrecognized option: $1"
+        ;;
+    esac
+  done
+
+  initial_cwd_=$PWD
+  ME_=`expr "./$0" : '.*/\(.*\)$'`
+
+  pfx_=`testdir_prefix_`
+  test_dir_=`mktempd_ "$initial_cwd_" "$pfx_-$ME_.XXXX"` \
+    || fail_ "failed to create temporary directory in $initial_cwd_"
+  cd "$test_dir_"
+
+  # This pair of trap statements ensures that the temporary directory,
+  # $test_dir_, is removed upon exit as well as upon catchable signal.
+  trap remove_tmp_ 0
+  trap 'Exit $?' 1 2 13 15
+}
+
+# Create a temporary directory, much like mktemp -d does.
+# Written by Jim Meyering.
+#
+# Usage: mktempd_ /tmp phoey.XXXXXXXXXX
+#
+# First, try to use the mktemp program.
+# Failing that, we'll roll our own mktemp-like function:
+#  - try to get random bytes from /dev/urandom
+#  - failing that, generate output from a combination of quickly-varying
+#      sources and gzip.  Ignore non-varying gzip header, and extract
+#      "random" bits from there.
+#  - given those bits, map to file-name bytes using tr, and try to create
+#      the desired directory.
+#  - make only $MAX_TRIES_ attempts
+
+# Helper function.  Print $N pseudo-random bytes from a-zA-Z0-9.
+rand_bytes_()
+{
+  n_=$1
+
+  # Maybe try openssl rand -base64 $n_prime_|tr '+/=\012' abcd first?
+  # But if they have openssl, they probably have mktemp, too.
+
+  chars_=abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
+  dev_rand_=/dev/urandom
+  if test -r "$dev_rand_"; then
+    # Note: 256-length($chars_) == 194; 3 copies of $chars_ is 186 + 8 = 194.
+    dd ibs=$n_ count=1 if=$dev_rand_ 2>/dev/null \
+      | tr -c $chars_ 01234567$chars_$chars_$chars_
+    return
+  fi
+
+  n_plus_50_=`expr $n_ + 50`
+  cmds_='date; date +%N; free; who -a; w; ps auxww; ps ef; netstat -n'
+  data_=` (eval "$cmds_") 2>&1 | gzip `
+
+  # Ensure that $data_ has length at least 50+$n_
+  while :; do
+    len_=`echo "$data_"|wc -c`
+    test $n_plus_50_ -le $len_ && break;
+    data_=` (echo "$data_"; eval "$cmds_") 2>&1 | gzip `
+  done
+
+  echo "$data_" \
+    | dd bs=1 skip=50 count=$n_ 2>/dev/null \
+    | tr -c $chars_ 01234567$chars_$chars_$chars_
+}
+
+mktempd_()
+{
+  case $# in
+  2);;
+  *) fail_ "Usage: $ME DIR TEMPLATE";;
+  esac
+
+  destdir_=$1
+  template_=$2
+
+  MAX_TRIES_=4
+
+  # Disallow any trailing slash on specified destdir:
+  # it would subvert the post-mktemp "case"-based destdir test.
+  case $destdir_ in
+  /) ;;
+  */) fail_ "invalid destination dir: remove trailing slash(es)";;
+  esac
+
+  case $template_ in
+  *XXXX) ;;
+  *) fail_ "invalid template: $template_ (must have a suffix of at least 4 
X's)";;
+  esac
+
+  fail=0
+
+  # First, try to use mktemp.
+  d=`env -u TMPDIR mktemp -d -t -p "$destdir_" "$template_" 2>/dev/null` \
+    || fail=1
+
+  # The resulting name must be in the specified directory.
+  case $d in "$destdir_"*);; *) fail=1;; esac
+
+  # It must have created the directory.
+  test -d "$d" || fail=1
+
+  # It must have 0700 permissions.  Handle sticky "S" bits.
+  perms=`ls -dgo "$d" 2>/dev/null|tr S -` || fail=1
+  case $perms in drwx------*) ;; *) fail=1;; esac
+
+  test $fail = 0 && {
+    echo "$d"
+    return
+  }
+
+  # If we reach this point, we'll have to create a directory manually.
+
+  # Get a copy of the template without its suffix of X's.
+  base_template_=`echo "$template_"|sed 's/XX*$//'`
+
+  # Calculate how many X's we've just removed.
+  template_length_=`echo "$template_" | wc -c`
+  nx_=`echo "$base_template_" | wc -c`
+  nx_=`expr $template_length_ - $nx_`
+
+  err_=
+  i_=1
+  while :; do
+    X_=`rand_bytes_ $nx_`
+    candidate_dir_="$destdir_/$base_template_$X_"
+    err_=`mkdir -m 0700 "$candidate_dir_" 2>&1` \
+      && { echo "$candidate_dir_"; return; }
+    test $MAX_TRIES_ -le $i_ && break;
+    i_=`expr $i_ + 1`
+  done
+  fail_ "$err_"
+}
+
+# If you want to override the testdir_prefix_ function,
+# or to add more utility functions, use this file.
+test -f $srcdir/init.cfg \
+  && . $srcdir/init.cfg
+
+setup_ "$@"
--
1.6.6.rc0.236.ge0b94