[Richard Suchenwirth] 2008-01-23 - Here is a little "application server" that waits for the existence of a specified file, reads it, deletes it, and executes its contents, line by line. It can be useful to trigger some action on a remote computer to whose file system you have write access, so you can send "orders" by writing to the magic file... No warranties, currently Windows only (use sh -c for Linux). Silly little example: * Start:
filewait hello > hello.log * Send an order: $ echo > hello df -k . After some seconds, the last lines of hello.log are (in my case) 2008-01-23T14:58:18 hello: 1 > df -k . 2008-01-23T14:58:23< 0 Filesystem 1k-blocks Used Available Use% Mounted on d: 156288320 154001928 2286392 99% / ---- #!/usr/bin/env tclsh set usage { filewait.tcl -- wait for a specified file, execute its contents Example: filewait.tcl mycmd.txt > mycmd.log The program deletes the waited-for file and keeps waiting. } proc main argv { if {[llength $argv] != 1} {puts stderr $::usage; exit 1} set ::waitfile [lindex $argv 0] puts stderr "waiting for $::waitfile, Ctrl-C to terminate..." every 1000 { if {[file exists $waitfile]} { set f [open $waitfile] set content [read $f] close $f file delete $waitfile set lineno 0 foreach line [split $content \n] { if {[string trim $line] eq ""} continue puts "[timestamp] $waitfile: [incr lineno] > $line" set rc [catch {exec cmd /c $line} res] puts "[timestamp]< $rc $res" flush stdout } } } vwait forever } proc every {ms body} {uplevel \#0 $body; after $ms [info level 0]} proc timestamp {} {clock format [clock seconds] -format %Y-%m-%dT%H:%M:%S} main $argv !!!!!! %| [Category Example] |% !!!!!!