There are multiple answers on the same for python and perl but I am unable to find any example for tcl. Basically the intention is to read the output of grep into tcl procedure via pipe. I tried
grep -ri --color -n WRN warnings.log | lint.tcl
content of lint.tcl:
#! /usr/bin/tclsh
lappend a [gets stdin]
puts "[join $a \n]"
But this outputs only first line of the grep match. Is there a while condition around [gets stdin] which can help?
Yes, I suggest you to use a while loop.
Actually, the issue is that [gets stdin] reads only a single line, so your script stops after reading the first line of output from grep.
To read all lines from stdin, you should wrap [gets stdin] in a while loop that continues until end-of-file. I would modify lint.tcl script in this way:
#!/usr/bin/tclsh
set a {}
while {[gets stdin line] >= 0} {
lappend a $line
}
puts "[join $a \n]"
And so you run:
grep -ri --color -n WRN warnings.log | ./lint.tcl
This should now output all matching lines from grep, not just the first one.