Create temporary script if a pipeline or control flow statement is used in sudo mode.

Earlier versions used to create a temporary script wherever a pipe symbol
or whitespace had been found in the command line.  This was an overkill,
and was removed in ff1b746d.  However, this approach is still needed, if
a pipeline or shell control structure is passed as command in sudo mode.
This commit restores it for such cases.  Another way would be to run
/bin/sh -c 'cmd', but that requires a careful preprocessing of cmd, so
I prefer a temporary, at least for the time being.

* rex (maketempfile): Register the created file in the global
list for further removal before exiting.
(editdb): Setting trap not needed now.
(cleanup): Remove files listed in cleanup_files
(ispipeline): New function
(rex_command): Fall back to copy mode when passing what looks like a
pipeline or control flow statement in sudo mode.
(MAIN): Set trap.

1 files changed, 36 insertions, 5 deletions

diff --git a/rex b/rex
index b0eb7dd..b2e0ff9 100755
--- a/rex
+++ b/rex
@@ -961,8 +961,10 @@ proc echo {a} {
 }
 
 proc maketempfile {} {
+    global cleanup_files
     set tempfile ".rex.[pid].tmp"
     exec "/bin/sh" -c "umask 077; touch $tempfile"
+    lappend cleanup_files $tempfile
     return $tempfile
 }
 
@@ -1185,10 +1187,6 @@ proc editdb {dbname} {
 	set ed "vi"
     }
 
-    trap {
-	file delete $tempfile
-	exit
-    } [list SIGINT SIGQUIT SIGHUP SIGTERM]
     set tempfile [maketempfile]
 
     mkdbview $dbname $tempfile rexdb
@@ -1997,9 +1995,18 @@ proc common_config_setup {} {
 proc cleanup {} {
     global argv0
     global errors
+    global cleanup_files
     
     debug 1 "cleaning up"
     updatedb
+
+    if {[info exist cleanup_files]} {
+	foreach fname $cleanup_files {
+	    file delete $fname
+	}
+	unset cleanup_files
+    }
+    
     if {[info exist errors]} {
 	send_error "$argv0: there were [llength $errors] errors:\n"
 	foreach err $errors {
@@ -2050,6 +2057,14 @@ proc regsub-eval {args} {
 	       \[[regsub -all {&} $cmd {\\&}]\]]
 }
 
+# Return true, if cmd looks like a pipeline or shell construct.
+proc ispipeline {cmd} {
+    if {[llength $cmd] != 1} {
+	return 0
+    }
+    regexp -- {(^(if|case|for|while|time|function|select)[[:space:]])|[|&><;]} $cmd
+}
+
 proc rex_command args {
     global argv0
     global argc
@@ -2207,6 +2222,17 @@ proc rex_command args {
     set config(argv) $newcom
     set config(command) [join $config(argv)]
     
+    if {$config(sudo) != "" && [ispipeline $config(argv)]} {
+	set tempscriptname [maketempfile]
+	debug 1 "creating temporary script file $tempscriptname"
+        set fd [open $tempscriptname w]
+        puts $fd $config(command)
+        close $fd
+	set config(command) $tempscriptname
+	set config(argv) $config(command)
+	set config(option,copy) 1
+    }
+    
     if {[llength $config(argv)] == 1 &&
 	[regexp {^(.+?)([[:space:]|&><;].*)$} $config(command) x config(progname) config(params)]} {
 	# nothing
@@ -2214,7 +2240,7 @@ proc rex_command args {
 	set config(progname) [lindex $config(argv) 0]
 	set config(params) [join [lrange $config(argv) 1 end]]
     }
-    
+
     if {[config_option copy]} {
 	lappend config(data) $config(progname)
 	set config(command) "[getiterpreter $config(progname)] [file tail $config(progname)] $config(params)"
@@ -2601,6 +2627,11 @@ if {$argc == 0} {
 
 set config(mode) [argcvshift]
 
+trap {
+    cleanup
+    exit
+} {SIGINT SIGQUIT SIGHUP SIGTERM}
+
 switch -- $config(mode) {
     run            -
     command        rex_command