tcl: regexp matching special character

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting tcl: regexp matching special character
# 1  
Old 01-09-2008
tcl: regexp matching special character

Hello Experts,

Can someone help me here:

I have a variable which contains a string with "[]".

set var1 {a[1]}
set str1 {a[1] is the element i want to match}

Now "regexp $var1 $str1" does not work?
("regexp {a\[1\]} $str1" works, but var1 gets it's value automatically from another script)

Is there a way to make it work?
(adding backslash "\" to var1 might not be feasible)
# 2  
Old 01-09-2008
% regexp {[$var1]} $str1

# 3  
Old 01-09-2008
doesn't look right to me

Can you explain 'How it works?'?

It doesn't seem right to me.

% set var1 {a[1]}
% set str1 {a[1] is the element i want to match}
a[1] is the element i want to match
% regexp $var1 $str1
% regexp {[$var1]} $str1
% set var1 {a[10]}
% regexp {[$var1]} $str1
% set var1 {a[9080]}
% regexp {[$var1]} $str1
# 4  
Old 01-09-2008
If you want a substring exact match that doesn't really rely on regexp syntax look at string match instead, but ymmv. I'm having trouble obtaining a sane result.You can always brute force the search..something like.

proc paramSearch {pattern str} {
set t [string length $pattern]
                for {set i 0} {$i < [string length $str]} {incr i $t} {
                    if {[string compare $pattern [string range $str $i [expr $i + [ expr $t - 1]]]] == 0} {return 1; #puts "Match at string index: $i"}
                    #puts "Compared $pattern and [string range $str $i [expr $i + [ expr $t - 1]]]"
() 92 % set vv
() 93 % set pat
() 94 % paramSearch $pat $vv

# 5  
Old 01-09-2008
Off by one...
proc paramSearch {pattern str} {
set t [expr [string length $pattern] - 1]
                for {set i 0} {$i < [string length $str]} {incr i $t} {
                    if {[string compare $pattern [string range $str $i [expr $i + $t]]] == 0} {return 1; #puts "Match at string index: $i"}
                    #puts "Compared $pattern and [string range $str $i [expr $i + $t]]"

# 6  
Old 01-09-2008
i would rather use lsearch

i was trying to understand if (and how) that can be done with 'regexp'?


lsearch -exact $str1 $var1

does the job pretty well.

% set var1 {a[1]}
% set var2 {aa[1]}
% set var3 {a[11]}
% set str1 {a[1] is the element we are looking for and not aa[1] or a[11]}
a[1] is the element we are looking for and not aa[1] or a[11]

% lsearch -exact $str1 $var1
% lsearch -exact $str1 $var2
% lsearch -exact $str1 $var3
# 7  
Old 01-09-2008
I can't make the regexp code behave as anticipated, thus the workaround.
Worse, the string match code seems fundamentally unhappy with brackets.

I'd approach comp.lang.tcl with this issue and/or check out the tclers wiki and
see if any articles are on point. The Tcler's Wiki
The lsearch idea is a okay but forces an abstraction from one
implicit type to another without solving the underlying problem and
possibly causing others...
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

TCL script to delete a pattern(regexp)

Hi I am writing a TCL script to delete a certain in a file My Input file module bist_logic_inst(a, ab , dhd, dhdh , djdj, hdh, djjd, jdj, dhd, dhp, dk ); input a; input ab; input dhd; input djdj; input dhd; output hdh; output djjd; output jdj; output dk; (1 Reply)
Discussion started by: kshitij
1 Replies

2. Shell Programming and Scripting

Special Character issue in Expect Utility (Tcl)

Hi, I have written a unix expect utility "ssh-login.exp" which connects (ssh) to remote host and execute some shell script. I am calling this "ssh-login.exp" utility from another shell script. "ssh-login.exp" takes username, password, host and shell script path to execute on remote host. All... (1 Reply)
Discussion started by: Mahesh Desai
1 Replies

3. Shell Programming and Scripting

Help using regexp in a TCL script ??

In a tcl script I need to find a way of reading a file, and looking for a phrase ("set myvariable") and putting the word following that into a variable. I've used a file open, and a while loop with gets to read each line from the file into a variable, and using regexp searched for the item. I'm... (1 Reply)
Discussion started by: Tonyb61
1 Replies

4. Shell Programming and Scripting

Merging two special character separated files based on pattern matching

Hi. I have 2 files of below format. File1 AA~1~STEVE~3.1~4.1~5.1 AA~2~DANIEL~3.2~4.2~5.2 BB~3~STEVE~3.3~4.3~5.3 BB~4~TIM~3.4~4.4~5.4 File 2 AA~STEVE~AA STEVE WORKS at AUTO COMPANY AA~DANIEL~AA DANIEL IS A ELECTRICIAN BB~STEVE~BB STEVE IS A COOK I want to match 1st and 3rd... (2 Replies)
Discussion started by: crypto87
2 Replies

5. Shell Programming and Scripting

Regexp in tcl

I need to change R3.1.5 as 03015 similarly R4.1.7 as 04017 i need a single command in tcl pls help ---------- Post updated at 05:19 PM ---------- Previous update was at 04:48 PM ---------- i had to do like this without using regexp set old_release "R3.1.5" ... (1 Reply)
Discussion started by: Syed Imran
1 Replies

6. Shell Programming and Scripting

Question on regexp in TCL

I need some help with regexp in tcl. The following code does work if the $urlvar ends in jpg,jpeg,png or gif. Eg, protocol(http/https):// if { ! } { //Do something } My problem is that if the URL does not end in these extensions this regexp is of no... (1 Reply)
Discussion started by: ampak
1 Replies

7. Shell Programming and Scripting

Question on TCL regexp and match

Hello everyone, I'm new in tcl scripting. I'm currently studying a tcl script and came across this line: regexp {(\d+)(\S?)} $opts match opt swi According to my understanding, this line means to search in the opts variable for one or more digit, followed by a non-whitespace character... (2 Replies)
Discussion started by: mar85
2 Replies

8. Shell Programming and Scripting

matching regexp

Hi, maybe it is stupid question, but is it possible to match expression like this ? : ... // ... ( there is "//" somewhere on the line and on the end of the line there ISN'T "*/" ) I've tried something like : (in SED) sed 's/\/\/' but I need "*/" not to be on the end of the line ...... (2 Replies)
Discussion started by: kolage
2 Replies

9. Shell Programming and Scripting

perl regexp matching

Hello, I cannot see what's wrong in my code. When I run code below, it just print an empty string. my $test = ""; if ($test = ~ m/\~{1,2}.*4/) { print "$1\n"; } else { print "No match...\n"; } Anyone know what I'm doing wrong? ... (4 Replies)
Discussion started by: urandom
4 Replies

10. Shell Programming and Scripting

pattern matching on any special character in Unix

Hi, I have field in a file which would come with any special character, how do i check that field? Eg: @123TYtaasa>>>/ 131dfetr_~2 In the above example, how do I add pattern for any special character on the keyboard. Thanks (3 Replies)
Discussion started by: techmoris
3 Replies
Login or Register to Ask a Question

Featured Tech Videos