New option --edit (-E) to edit the credentials database.

1 files changed, 136 insertions, 5 deletions

diff --git a/rex b/rex
index 9a5a134..d6d779d 100755
--- a/rex
+++ b/rex
@@ -32,6 +32,7 @@ array set rexdb {}
 
 catch {set config(prompt) $env(EXPECT_PROMPT)}
 
+# Return the value of the configuration option KEY
 proc config_option {key} {
     global config
     if {![info exists config(option,$key)]} {
@@ -40,6 +41,8 @@ proc config_option {key} {
     return $config(option,$key)
 }
 
+# rexdbget KEY [KEY...]
+# Iterate over KEYs, find first of them that is defined and return its value.
 proc rexdbget {args} {
     global rexdb
 
@@ -59,6 +62,7 @@ proc rexdbget {args} {
     }
 }
 
+# rexdbput KEY VALUE [KEY VALUE...]
 proc rexdbput {args} {
     global rexdb
 
@@ -82,6 +86,7 @@ proc rexdbput {args} {
     set rexdb(updated) 1
 }   
 
+# rexdbclr KEY...
 proc rexdbclr {args} {
     global rexdb
 
@@ -132,12 +137,14 @@ proc echo {a} {
     }
 }
 
+# Print program usage instructions
 proc prusage {} {
-    global argv0
+    global argv0 usrconfdir
     
     puts "usage: $argv0 \[OPTIONS\] \[COMMAND ARGS...\]"
     puts "   or: $argv0 \[OPTIONS\] -c SRC... DST"
     puts "   or: $argv0 \[sudo\] shell HOST"
+    puts "   or: $argv0 --editdb \[FILE\]"
     puts "   or: $argv0 -e \[WORD...\]"
     puts ""
     puts "Rex executes a command on several hosts." 
@@ -146,12 +153,15 @@ proc prusage {} {
 
   -d, --debug       increase debugging level	
   -H, --host NAME   add host to the list
+  -E, --editdb [FILE]
+	            edit the database file (default ~/.rex/db)
   -e, --encrypt [WORD]
 	            encrypt the WORD (read it from the stdin if not supplied),
 	            and print out the result
   -N, --noop        ignore all commands (useful for side effects)
   -u, --user NAME   log in as user NAME
-  -p, --pass PWD    set password (unsafe!)
+  -p, --password PWD
+	            set password (unsafe!)
   -c, --cp, --copy  copy arguments to each host (see the 2nd form above)
   -C, --config FILE read config from FILE
       --list-groups list available host groups
@@ -171,6 +181,7 @@ Report bugs to <gray+rex@gnu.org.ua>
     exit 0
 }
 
+# Print program version and copyleft info.
 proc prversion {} {
     global version
     
@@ -183,6 +194,9 @@ There is NO WARRANTY, to the extent permitted by law.
     exit 0
 }
 
+# getans [-echo] WORDS...
+# Concat WORDS into a prompt, display it, read the user's input from stdin
+# and return it.  The -echo option turns echo off (for inputting passwords).
 proc getans {args} {
     if {[lindex $args 0] == "-echo"} {
 	set noecho 1
@@ -204,6 +218,9 @@ proc getans {args} {
     return $retval
 }
 
+# getyn WORDS
+# Same as getans, but restrict user input to Y, N, and <CR>.  Return true
+# if the user replied Y (or <CR>), and false otherwise.
 proc getyn {args} {
     lappend args { [Y/n]?}
     switch -glob [string trimleft [getans [eval concat $args]] " \t"] {
@@ -213,21 +230,26 @@ proc getyn {args} {
     }
 }
 
+# Encrypt password
 proc passenc {pass} {
     binary scan [encoding convertto ebcdic $pass] H* enc
     return $enc
 }
 
+# Decrypt password
 proc passdec {code} {
     encoding convertfrom ebcdic [binary format H* $code]
 }
 
+# Read rex database FILE into VAR
 proc readdb {file var} {
     upvar $var x
 
     debug 2 reading database file $file
     set fd [open $file "r"]
+    set lnum 0
     while {[gets $fd line] >= 0} {
+	incr lnum
 	regsub {[ \t]*#.*} [string trimright $line] "" line
         if [regexp {(.+)[ \t]+(.*)} "$line" dummy key val] {
 		set x($key) $val
@@ -236,6 +258,7 @@ proc readdb {file var} {
     close $fd
 }
 
+# Auxiliary function to compare two keys
 proc keycmp {a b} {
     foreach ka [split $a ":"] kb [split $b ":"] {
 	set x [string compare $ka $kb]
@@ -245,7 +268,8 @@ proc keycmp {a b} {
     }
     return 0
 }
-    
+
+# Write rex database from variable VAR into FILE.
 proc writedb {file var} {
     upvar $var x
 
@@ -257,7 +281,8 @@ proc writedb {file var} {
     close $fd
     file rename -force ${file}.tmp $file
 }
-    
+
+# Update rexdb if it has been modified.
 proc updatedb {} {
     global rexdb confpath
 
@@ -268,6 +293,95 @@ proc updatedb {} {
     }
 }
 
+# Prepare a temporary "database view" file.
+#  dbname   - name of the original file
+#  tempfile - temporary output file name
+#  dbvar    - array variable to get key/value pairs from.
+proc mkdbview {dbname tempfile dbvar} {
+    upvar $dbvar db
+    set fd [open $tempfile w]
+    puts $fd "# You are editing file $dbname"
+    puts $fd [format "# %-30.30s\t%s" "Key" "Value"]
+    foreach key [lsort -command keycmp [array names db]] {
+	if {$key == "pass" ||
+	    [string last ":pass" $key] == [expr [string length $key] - 5]} {
+	    puts $fd [format "%-32.32s\t%s" $key [passdec $db($key)]]
+	} else {
+	    puts $fd [format "%-32.32s\t%s" $key $db($key)]
+	}
+    }
+    close $fd
+}    
+
+# Save modified dbview from tempfile into outfile
+proc svdbview {tempfile outfile} {
+    array set x {}
+    readdb $tempfile x
+    foreach key [array names x] {
+	if {$key == "pass" ||
+	    [string last ":pass" $key] == [expr [string length $key] - 5]} {
+	    set x($key) [passenc $x($key)]
+	}
+    }
+    writedb $outfile x
+}
+
+# Ask user about his further intentions.
+proc whatnow {} {
+    while true {
+	set reply [getans {What now ([s]ave, [q]uit, [e]dit again)?}]
+	switch -nocase $reply {
+	    s -
+	    sa -
+	    sav -
+	    save  { return "s" }
+	    q -
+	    qu -
+	    qui -
+	    quit  { return "q" }
+	    e -
+	    ed -
+	    edi -
+	    edit  { return "e" }
+	}
+    }
+}
+
+# Edit database file dbname.  The file is formatted in a more or less
+# human-readable way, stored in a temporary file and an editor is started
+# on that file. 
+proc editdb {dbname} {
+    array set rexdb {}
+
+    readdb $dbname rexdb
+    
+    if [info exist env(VISUAL)] {
+	set ed $env(VISUAL)
+    } elseif [info exist env(EDITOR)] {
+	set ed $env(EDITOR)
+    } else {
+	set ed "vi"
+    }
+    
+    set tempfile ".rex.[pid].tmp"
+    exec "/bin/sh" -c "umask 077; touch $tempfile"
+
+    mkdbview $dbname $tempfile rexdb
+    while 1 {
+	exec $ed $tempfile
+	switch [whatnow] {
+	    e continue
+	    q break
+	    s {
+		svdbview $tempfile $dbname
+		break
+	    }
+	}
+    }
+    file delete $tempfile
+}
+
+# Return user name for the given host.
 proc hostuser {host} {
     global config
 
@@ -298,6 +412,7 @@ proc hostuser {host} {
     error "no default username (shouldn't happen)"
 }
 
+# Return user password for the given host
 proc hostpass {host} {
     global rexdb config
 
@@ -329,6 +444,7 @@ proc hostpass {host} {
     return ""
 }
 
+# List available host groups.
 proc listgroups {} {
     global confpath argv0
     
@@ -548,7 +664,7 @@ proc getopt {args} {
     return 0
 }
 
-set shortopts "Ccdeig:HhlNp:Ss:u:x:Vw"
+set shortopts "CcdeEig:HhlNp:Ss:u:x:Vw"
 set longopts {
     debug         d
     host          H
@@ -568,6 +684,7 @@ set longopts {
     confirm       w
     list-groups   -
     noop          N
+    editdb        E
 }
 
 set optind 0
@@ -602,6 +719,7 @@ getopt -progname $argv0 -longopts $longopts $argc $argv $shortopts {
 	list-groups { listgroups
 	              exit 0
 	}
+	E { set config(option,editdb) 1 }
 	h prusage
 	V prversion
 	default { exit 1 }   
@@ -611,6 +729,19 @@ getopt -progname $argv0 -longopts $longopts $argc $argv $shortopts {
 set argv [lrange $argv $optind end]
 set argc [expr $argc - $optind]
 
+if [config_option editdb] {
+    if {$argc >= 1} {
+	set dbname [lindex $argv 0]
+    } elseif [file readable "$usrconfdir/db"] {
+	set dbname "$usrconfdir/db"
+    } else {
+	puts stderr "$0: no db file to edit"
+	exit 1
+    }
+    editdb $dbname
+    exit 0
+}
+
 if [info exists config(option,hostgroup)] {
     debug 1 "using hostgroup $config(option,hostgroup)"
     set libpath [linsert libpath 0 \