Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

RegExp question

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting RegExp question
# 1  
Old 06-28-2005
RegExp question
Hi guys,

does anyone know how to test for a regular expression - i want to include it in a script to make sure the variable is a regexp

cheers
# 2  
Old 06-28-2005
There is no such way, everything could be a regular expression.

If there is a string "file" it could be a regexp too - one that matches the word "file" and nothing else.

bakunin
# 3  
Old 06-28-2005
You could check for whether a variable is a valid regular expression.

Code:
check_re_valid() {
    grep -- "$1" < /dev/null 2>/dev/null
    if [ $? -eq 2 ]; then
        return 1
    else
        return 0
}

# 4  
Old 06-28-2005
penfold,

Read the rules.

(4) Do not 'bump up' questions if they are not answered promptly. No duplicate or cross-posting and do not report a post where your goal is to get an answer more quickly.

Thanks !
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. What is on Your Mind?

A Regexp You Can Use Everywhere

¯\_(ツ)_/¯ bakunin (0 Replies)
Discussion started by: bakunin
0 Replies

2. Shell Programming and Scripting

Regexp

I would like to extract "1333 Fairlane" given the below text. The word "Building:" is always present. The wording between Building and the beginning of the address can be almost anything. It appears the the hyphen is there most of the time. Campus: Fairlane Business Park Building:... (9 Replies)
Discussion started by: bbaker@copesan.
9 Replies

3. 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)://testsite.com/images/image1.jpg 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

4. 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

5. Shell Programming and Scripting

help with grep regexp

My input file looks like this: 13154|X,the deer hunter 13154|Y,the good life 1316|,american idol 1316|,bowling 1316|,chuck etc... The X, Y, or any other character (besides a comma) after the pipe is a "Device Type". I want to strip out lines that do not have a device type. I have... (2 Replies)
Discussion started by: jwinsk
2 Replies

6. UNIX for Dummies Questions & Answers

print the line immediately after a regexp; but regexp is a sentence

Good Day, Im new to scripting especially awk and sed. I just would like to ask help from you guys about a sed command that prints the line immediately after a regexp, but not the line containing the regexp. sed -n '/regexp/{n;p;}' filename What if my regexp is 3 word or a sentence. Im... (3 Replies)
Discussion started by: ownins
3 Replies

7. Shell Programming and Scripting

Help with regexp

Hi there! I would like to know how to find and replace all numbers in a *.html file and make them bold. Any help will be appreciated! :) (7 Replies)
Discussion started by: agasamapetilon
7 Replies

8. Shell Programming and Scripting

regexp help

I'd like to know if there is a catchall line for renaming the following patterns: s01e03 -> 01x03 s4e9 -> 04x09 s10e08 ->10x08 and possibly even: 318 -> 03x18 1002 ->10x02 if its the first 3 or first digit number in the string. thanks! (0 Replies)
Discussion started by: TinCanFury
0 Replies

9. UNIX for Advanced & Expert Users

regexp

Hi guys, does anyone know how to test for a regular expression - i want to include it in a script to make sure the variable is a regexp cheers (1 Reply)
Discussion started by: penfold
1 Replies

10. UNIX for Dummies Questions & Answers

vi + regexp + substitute

Another enigma (for me) Using VI I edit some files in which I want to erase many lines I don't need anymore usually I do something like that::%s/line_to_suppress//g and it is doing fine but in this case, the pattern to erase contains some special characters so I do it like... (9 Replies)
Discussion started by: Lomic
9 Replies
Login or Register to Ask a Question