How to execute the Linux command from a TCL shell?

Question

I am executing following command successfully from linux env,

[UdayaShankar Das@lxapp-3]# tshark -r sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*\s\(\(\s[0-9a-f][0-9a-f]\)\{1,16\}\).*$/\1/p'

ff ff ff ff ff ff 00 10 94 00 00 0a 08 06 00 01 08 00 06 04 00 01 00 10 94 00 00 0a c0 01 01 02 00 00 00 00 00 00 c0 01 01 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

bu the above command failing when trying from tcl shell through exec command and back tik operator . Please advise.

% [ exec tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap  -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p' ]
 invalid command name "0-9a-f"

UPDATE:

thanks for your suggestion. I tried but seems not working :(

  % set cmd34 {tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p'}
 tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p'
 % [ eval exec $cmd34]
 invalid command name "0-9a-f"

Also tried with second option

%set cmd34 {tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p'}
 tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p'
 % [ exec {*}$cmd34 ]
 extra characters after close-brace

Donal Fellows Donal Fellows · Accepted Answer · 2014-10-20T14:35:23

When you have a chunk of shell script like this:

tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap  -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p'

The simplest method of running it is to use:

set shellscript {tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap  -Vx -R frame.number==2 | sed -n 's/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p'}
set response [exec /bin/sh -c $shellscript]

Alternatively, change the single quote characters to braces:

exec tshark -r /home/arts2/STC_CAPTURE/sim_venom_sanity_DEVICE1_PORT1_1_capture.pcap  -Vx -R frame.number==2 | sed -n {s/^[0-9a-f]*s((s[0-9a-f][0-9a-f]){1,16}).*^A/p}

How to execute the Linux command from a TCL shell?

2 Answers