Search a section of text, which occurs regularly in tcl - parsing

Question

I have a file called log_file with following text:
....some text....
line wire (1)
mode : 2pair , annex : a
coding : abcd
rate : 1024
status : up
....some text....
line wire (2)
mode : 4pair , annex : b
coding : xyz
rate : 1024
status : down
....some text....
The values may differ but the attributes are always the same. Is there a way to find each line wire and display their attributes? The number of line wires also may differ.
EDIT: File doesn't have any blank lines. There are more attributes but only these are needed. Can I get like the first "n" lines, instead of searching for every line? i.e if there is line wire (1), copy that line plus the next 4 lines.
And I am copying the searched lines to a output file $fout, which I have used earlier in the script with the same $line.

Answer 1

Given your sample:
set fh [open log_file r]
while {[gets $fh line] != -1} {
switch -glob -- $line {
{line wire*} {puts $line}
{mode : *} -
{coding : *} -
{rate : *} -
{status : *} {puts " $line"}
}
}
close $fh
outputs
line wire (1)
mode : 2pair , annex : a
coding : abcd
rate : 1024
status : up
line wire (2)
mode : 4pair , annex : b
coding : xyz
rate : 1024
status : down
Edit: print the next "n" lines following the "line wire" line to a file
set in [open log_file r]
set out [open log_file_filtered w]
set n 4
while {[gets $in line] != -1} {
if {[string match {line wire*} $line]} {
puts $line
for {set i 1} {$i <= $n} {incr i} {
if {[gets $in line] != -1} {
puts $out " $line"
}
}
}
}
close $fh