''Martin S. Weber''

 Ephaeton at gmx dot net

 Homepage still under construction :)

Wiki stuff:

    * [Errx]
    * [AtExit Handlers]
    * Some socket examples in [Einfach Tcl]
    * [pathentry]
    * [block-select]
    * [sizepanel]
    * multiple value [set]
    * likes [Toasting procs]
    * [Simpletracer], with help from [RS] & [MS]

Next to come:
    * finish [sizepanel]
    * finish [pathentry]
    * onInit
    * Remarks about gcc
----
[Category Person]

----
This is for suchenwi/ tcl chatroom:

 set ::bexec_runs 0
 set ::bexec_result ""
 set ::bnum 0

 proc bexec what {
	global bexec_runs bexec_result bnum
        incr bnum
        set fname [file join $::env(HOME) tmp cmd_run_lock_$::env(USER)_[pid]]
	while {[catch {set fp [open $fname {WRONLY CREAT EXCL}]}]}  {
			puts stderr "($bnum) Lock busy, will retry."
			after 200 "set ::retry 0"
			vwait ::retry
	}
	puts stderr "($bnum)Got the Lock for \"[string range $what 0 99]...\"."

	# reset results
	set ::bexec_result ""
	puts stderr "Executing $what..."
	set bexec_runs 1
	set f [open |$what]
	#fconfigure $f -translation none
	fileevent $f readable [list bexec_read $f]
	vwait bexec_runs
	file delete -force [file join $::env(HOME) tmp cmd_run_lock_$::env(USER)_[pid]]
	puts stderr "($bnum)Released the Lock for \"[string range $what 0 99]...\"."

	return $bexec_result
 }

 proc bexec_read {f} {
	set data [read $f]
	if [eof $f] {
		close $f
		set ::bexec_runs 0
	}
	append ::bexec_result $data
 }

 # demo1:
 set tfile [open tst.sh w]
 puts $tfile {#!/bin/sh
 echo "output1"
 sleep 3
 echo "output2"}
 close $tfile

 puts [bexec "sh tst.sh"]
 puts [bexec "sh tst.sh"] ;# <-- this one will wait.

 # demo2:
 pack [button .b -text "run" -command {puts [bexec "sh tst.sh"]}] -expand 1 -fill both

Output:

 (1)Got the Lock for "sh tst.sh...".
 (1)Executing sh tst.sh...
 (1)Released the Lock for "sh tst.sh...".
 output1
 output2

 (2)Got the Lock for "sh tst.sh...".
 (2)Executing sh tst.sh...
 (2)Released the Lock for "sh tst.sh...".
 output1
 output2

 (3)Got the Lock for "sh tst.sh...".
 (3)Executing sh tst.sh...
 (3)Released the Lock for "sh tst.sh...".
 output1
 output2

 (4)Got the Lock for "sh tst.sh...".
 (4)Executing sh tst.sh...
 (5) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 (6) Lock busy, will retry.
 # ad infitum... lockfile never goes away.

'''DKF VERSION'''
 set ::bexec_runs 0
 set ::bexec_result ""
 set ::bnum 0

 proc bexec {what handler {uid -1}} {
   global bexec_accum bnum
   if {$uid == -1} {
      set uid [incr bnum]
   }
   set fname [file join ~ tmp cmd_run_lock_[pid]]
   if {[catch {open $fname {WRONLY CREAT EXCL}} fp]} {
      puts stderr "($uid) Lock busy, will retry."
      after 200 [list bexec $what $handler $uid]
      return
   }
   set f [open |$what]
   set bexec_accum($uid) {}
   fileevent $f readable [list bexec_read $f $uid $fname $handler]
 }
 proc bexec_read {f uid fname handler} {
   global bexec_accum
   if {[gets $f line] == -1} {
      close $f
      file delete -force $fname
      uplevel #0 $handler [list $bexec_accum($uid)]
      unset bexec_accum($uid)
      return
   }
   append bexec_accum($uid) $line \n
 }
 # demo1:
 set tfile [open tst.sh w]
 puts $tfile {#!/bin/sh
 echo "output1"
 sleep 3
 echo "output2"}
 close $tfile

 bexec "sh tst.sh" puts
 bexec "sh tst.sh" puts ;# <-- this one will wait.

 # demo2:
 pack [button .b -text "run" -command {bexec "sh tst.sh" puts}] -expand 1 -fill both


Output:

 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 (2) Lock busy, will retry.
 output1
 output2

 output1
 output2

 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 (4) Lock busy, will retry.
 output1
 output2

 (5) Lock busy, will retry.
 (5) Lock busy, will retry.
 (5) Lock busy, will retry.
 output1
 output2

 output1
 output2