Provide an option to run commands via sh -c

The new flag "shell" instructs pies to run the command marked with it
as '/bin/sh -c $command'. Alternative shell can be supplied ising the
'program' statement.

This is useful if the command line uses shell-specific features (command
or variable expansion, redirection, pipes, etc.)

This commit also fixes a bug in the 'env' statement handling: a single
argument with embedded whitespaces was undergoing word splitting and
thus incorrectly handled as multiple arguments.

* NEWS: Document changes.
* doc/pies.texi: Likewise.
* src/comp.c (component_free): Free command.
(component_finish): Split command into argv/argc as directed by the
CF_SHELL flag.
* src/pies.c (_cb_command): Remove. Functionality moved to
component_finish().
(_cb_env): Bugfix. Don't split arguments.
* src/pies.h (CF_SHELL): New flag.
(component) <command>: New member.

* tests/Makefile.am: Add new tests.
* tests/testsuite.at: Add new tests.
* tests/aux/respawn: Change default timeout to 1 second.
* tests/respawn.at: Minor change.
* tests/shell.at: New test.

5 files changed, 62 insertions, 2 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index b404ed4..39899c8 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -52,6 +52,7 @@ TESTSUITE_AT = \
  redirect.at\
  ret-exec.at\
  ret-notify.at\
+ shell.at\
  startup.at\
  shutdown.at\
  version.at
diff --git a/tests/aux/respawn b/tests/aux/respawn
index 11d59f6..cd9687a 100755
--- a/tests/aux/respawn
+++ b/tests/aux/respawn
@@ -5,7 +5,7 @@
 
 append=0
 unset name
-time=10
+time=1
 tag=$0
 code=0
 
diff --git a/tests/respawn.at b/tests/respawn.at
index 4a8e3a7..6b51ca6 100644
--- a/tests/respawn.at
+++ b/tests/respawn.at
@@ -34,7 +34,7 @@ while :
 do
     if test -f $comp_pid_file; then
         lines=`wc -l $comp_pid_file | awk '{print $1}'`
-        if test "$lines" -ge 3 ; then
+        if test "$lines" -ge 2 ; then
             break
         fi
     fi  
diff --git a/tests/shell.at b/tests/shell.at
new file mode 100644
index 0000000..0ef2271
--- /dev/null
+++ b/tests/shell.at
@@ -0,0 +1,58 @@
+# This file is part of GNU pies testsuite. -*- Autotest -*-
+# Copyright (C) 2016-2019 Sergey Poznyakoff
+#
+# GNU pies is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU pies is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU pies.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([flags shell])
+
+AT_CHECK([
+PIES_XFAIL_CHECK
+PIES_CONTROL_INIT
+outfile=$PWD/respawn.out
+cat > pies.conf <<_EOT
+component test {
+        mode respawn;
+        flags shell;
+        command "$auxdir/respawn -tag respawn > $outfile";
+}
+_EOT
+
+pies --config-file control.conf --config-file pies.conf
+
+n=0
+while :
+do
+    if test -f $outfile; then
+        lines=`wc -l $outfile | awk '{print $1}'`
+        if test "$lines" -ge 2 ; then
+            break
+        fi
+    fi  
+    sleep 1
+    n=$(($n + 1))
+    if test $n -gt 35; then
+        echo >&2 "timed out"
+        break
+    fi
+done
+
+PIES_STOP
+head -n3 $outfile
+],
+[0],
+[respawn: start
+respawn: stop
+])
+
+AT_CLEANUP
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 6775ee7..28d1f9d 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -67,3 +67,4 @@ m4_include([ret-exec.at])
 m4_include([ret-notify.at])
 m4_include([startup.at])
 m4_include([shutdown.at])
+m4_include([shell.at])