find the line number where a specific word appears with “sed” on tcl shell - sed

Question

I need to search for a specific word in a file starting from specific line and return the line numbers only for the matched lines.
Let's say I want to search a file called myfile for the word my_word and then store the returned line numbers.
By using shell script the command :
sed -n '10,$ { /$my_word /= }' $myfile
works fine but how to write that command on tcl shell?
% exec sed -n '10,$ { /$my_word/= }' $file
extra characters after close-brace.
I want to add that the following command works fine on tcl shell but it starts from the beginning of the file
% exec sed -n "/$my_word/=" $file
447431
447445
448434
448696
448711
448759
450979
451006
451119
451209
451245
452936
454408
I have solved the problem as follows
set lineno 10
if { ! [catch {exec sed -n "/$new_token/=" $file} lineFound] && [string length $lineFound] > 0 } {
set lineNumbers [split $lineFound "\n"]
foreach num $lineNumbers {
if {[expr {$num >= $lineno}] } {
lappend col $num
}
}
}
Still can't find a single line that solve the problem
Any suggestions ??

Answer 1

I don't understand a thing: is the text you are looking for stored inside the variable called my_word or is the literal value my_word?
In your line
% exec sed -n '10,$ { /$my_word/= }' $file
I'd say it's the first case. So you have before it something like
% set my_word wordtosearch
% set file filetosearchin
Your mistake is to use the single quote character ' to enclose the sed expression. That character is an enclosing operator in sh, but has no meaning in Tcl.
You use it in sh to group many words in a single argument that is passed to sed, so you have to do the same, but using Tcl syntax:
% set my_word wordtosearch
% set file filetosearchin
% exec sed -n "10,$ { /$my_word/= }" $file
Here, you use the "..." to group.
You don't escape the $ in $my_word because you want $my_word to be substitued with the string wordtosearch.
I hope this helps.

Answer 2

After a few trial-and-error I came up with:
set output [exec sed -n "10,\$ \{ /$myword/= \}" $myfile]
# Do something with the output
puts $output
The key is to escape characters that are special to TCL, such as the dollar sign, curly braces.
Update
Per Donal Fellows, we do not need to escape the dollar sign:
set output [exec sed -n "10,$ \{ /$myword/= \}" $myfile]
I have tried the new revision and found it works. Thank you, Donal.
Update 2
I finally gained access to a Windows 7 machine, installed Cygwin (which includes sed and tclsh). I tried out the above script and it works just fine. I don't know what your problem is. Interestingly, the same script failed on my Mac OS X system with the following error:
sed: 1: "10,$ { /ipsum/= }": extra characters at the end of = command
while executing
"exec sed -n "10,$ \{ /$myword/= \}" $myfile"
invoked from within
"set output [exec sed -n "10,$ \{ /$myword/= \}" $myfile]"
(file "sed.tcl" line 6)
I guess there is a difference between Linux and BSD systems.
Update 3
I have tried the same script under Linux/Tcl 8.4 and it works. That might mean Tcl 8.4 has nothing to do with it. Here is something else that might help: Tcl comes with a package called fileutil, which is part of the tcllib. The fileutil package contains a useful tool for this case: fileutil::grep. Here is a sample on how to use it in your case:
package require fileutil
proc grep_demo {myword myfile} {
foreach line [fileutil::grep $myword $myfile] {
# Each line is in the format:
# filename:linenumber:text
set lineNumber [lindex [split $line :] 1]
if {$lineNumber >= 10} { puts $lineNumber}
}
}
puts [grep_demo $myword $myfile]

Answer 3

Here is how to do it with awk
awk 'NR>10 && $0~f {print NR}' f="$my_word" "$myfile"
This search for all line larger than line number 10 that contains word in variable $my_word in file name stored in variable myfile