Expect and ls -l *.sh

delevel · 05-28-2009, 01:44 AM

I get this error

Quote:

ls: cannot access *.sh: No such file or directory
while executing
"exec ls -l *.sh"
invoked from within
"set MYLIST [exec ls -l *.sh]"
(file "./myls.sh" line 2)

my code for myls.sh

Code:

#!/usr/bin/expect -f
set MYLIST [exec ls -l *.sh]
puts "$MYLIST"
exit

jlinkels · 05-28-2009, 07:20 AM

Tcl (and therefor Expect) doesn't do file name expansion, so everything passed to ls with a wildcard will fail.

This works:

Code:

#!/usr/bin/expect -f
set MYLIST [exec ls -l [glob *.sh] ]
puts "$MYLIST"
exit

Note that your program was terminated because the call to ls was considered failed. This is not usually wanted behaviour, not being able to find certain files is a valid result of ls, and that most of the times should not result in termination of your expect program.

You could consider putting the exec call in a catch {} construct so the program does not crash when ls fails.
http://www.hume.com/html84/mann/catch.html

jlinkels

delevel · 05-28-2009, 09:09 AM

Quote:

Originally Posted by jlinkels

Tcl (and therefor Expect) doesn't do file name expansion, so everything passed to ls with a wildcard will fail.

This works:

Code:

#!/usr/bin/expect -f
set MYLIST [exec ls -l [glob *.sh] ]
puts "$MYLIST"
exit

Note that your program was terminated because the call to ls was considered failed. This is not usually wanted behaviour, not being able to find certain files is a valid result of ls, and that most of the times should not result in termination of your expect program.

You could consider putting the exec call in a catch {} construct so the program does not crash when ls fails.
http://www.hume.com/html84/mann/catch.html

jlinkels

Thanks it works but got a other problem if there is more then one .sh file in that dir I get this insted

Quote:

ls: cannot access myls2.sh myls.sh: No such file or directory
while executing
"exec ls -l [glob *.sh] "
invoked from within
"set MYLIST [exec ls -l [glob *.sh] ]"
(file "./myls.sh" line 2)

is there a better way in expect to handel wildcards? so I can do a "ls -l *.sh" so it works like in shell?

jlinkels · 05-28-2009, 10:03 AM

Beats me...

When I tested it, I happened to have only one *.sh file in that directory. Now I have two files and I get the same error as you do.

[glob *.sh] as such returns a list with two file names.

When I write these two file names in the exec command verbatim I don't get an error:

Code:

set MYLIST [exec ls -l ppc_timing.sh another.sh]

works fine.

Now even when I do

Code:

set MYLIST [exec ls -l [join[glob *.sh]]]

and the outcome of [join[glob *.sh]] is exactly ppc_timing.sh another.sh, ls returns an error.

This works:

Code:

set MYLIST [exec ls -l [lindex[glob *.sh] 0]]

but again returns only one file name.

You could use a foreach loop as workaround. For the moment I have to stop looking as my boss starts looking at me.

jlinkels

jlinkels · 05-28-2009, 07:05 PM

This works:

Code:

set MYLIST [eval exec ls -l [glob *.sh]]

The eval expresion is needed to flatten the list produced by glob (so it is explained). If the list is not flattened, the argument passed to ls is ONE file name, with spaces in it, e.g. "file1.sh file2.sh" instead of "file1.sh" "file2.sh". It doesn't ring a bell why eval makes that work right, but it does. As a matter of fact it is a textbook example to use eval here: http://wiki.tcl.tk/1017

Also, study this page thoroughly:
http://www.tcl.tk/man/tcl8.5/tutorial/Tcl26.html

jlinkels

delevel · 05-29-2009, 01:37 AM

Thanks man you saved my day

I usually just program in PHP. Oh and thanks for taking the time and good links too.