get exit staus of command in tcl

[ramana35]

Hi,

Could somebody help me in getting exit staus of command in tcl.

if it is shell script we can use echo $? right, how can i do that in tcl ?


thanks in advance.


-Kamma

 

[feherke]

Hi

You mean, when you [tt]exec[/tt] an external command ?

Just [tt]catch[/tt] what it returns and extract it from its optionsVarName parameter :

[b]catch[/b] [teal]{[/teal][b]exec[/b] external_command[teal]}[/teal] result option
[b]puts[/b] [teal][[/teal]dict get [navy]$option[/navy] [teal]-[/teal]code[teal]][/teal]

Feherke.

http://feherke.github.com/

 

[ramana35]

Thanks for quick response.

Actually i would like to check if a user is existed or not.

so i can execute id username

can you describe me what puts [dict get $option -code] do ?
how can i exit if id username return error(means user not existed)

 

[feherke]

Hi

can you describe me what puts [dict get $option -code] do ?

Do a [tt]puts [navy]$option[/navy][/tt] to see the entire list populated by [tt]catch[/tt].

[tt]dict get[/tt] just searches a value in the odd elements in a list and if found, returns the matching even value :

[b]set[/b] whatever [green][i]"one two three four five six"[/i][/green]
[b]puts[/b] [teal][[/teal]dict get [navy]$whatever[/navy] three[teal]][/teal]
[gray]# outputs four[/gray]

how can i exit if id username return error(means user not existed)

[tt]id[/tt] returns non-zero exit code when no such user exists. It not depends on logged in status.


Feherke.

http://feherke.github.com/

 

[ramana35]

thanks, but


bash-2.05$ cat test.tcl
#!/usr/local/bin/tclsh

set var [lindex $argv 0]
puts $var

if { [catch {exec /usr/bin/groups $var} option] } {
puts [dict get $option -code]
}

bash-2.05$ test.tcl rk
rk
invalid command name "dict"
while executing
"dict get $option -code"
(file "./test.tcl" line 7)


Can you tell me how to get rid of this ?

 

[Bong]

dictionaries were introduced in 8.5 (I think). What version of Tcl are you using?

Anyway what do you get if you just "puts $option"?

_________________
Bob Rashkin

 

[feherke]

Hi

Good point Bob.

Kamma, optionsVarName is [tt]catch[/tt]'s 3[sup]rd[/sup] parameter, not 2[sup]nd[/sup].

The following workaround should work with older Tcl version too. Note that it reproduces strictly the extracting part, has absolutely no error checking :

[b]if[/b] [teal]{[/teal] [teal][[/teal][b]catch[/b] [teal]{[/teal][b]exec[/b] [teal]/[/teal]usr[teal]/[/teal]bin[teal]/[/teal]groups [navy]$var[/navy][teal]}[/teal] bla option[teal]][/teal] [teal]}[/teal] [teal]{[/teal]
  [b]puts[/b] [teal][[/teal][b]lindex[/b] [navy]$option[/navy] [teal][[/teal][b]lsearch[/b] [navy]$option[/navy] [teal]-[/teal]code[teal]]+[/teal][purple]1[/purple][teal]][/teal]
[teal]}[/teal]

Feherke.

http://feherke.github.com/

 

[ramana35]

below one worked for me.

if { ![catch {exec groups $user_or_scoped_pr} result] } {
puts "user exist"
{ else {

puts "user not exist"
exit
}

Anyways thanks.