Visit Our UNIX and Linux User Community


regex and grep


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting regex and grep
# 1  
Old 05-17-2009
regex and grep

I want it to find lines that contain any number of capital letters before P

this is what I have tried
Code:
echo "AAAAAP" | grep '[A-Z]P'
echo "AAAAAP" | grep '[A-Z]\{1\}P'
echo "AAAAAP" | grep '^[A-Z]*P'

But none of them seem to work, any help is much appreciated

thanks
Calypso
# 2  
Old 05-17-2009
Do the capital letters have to begin at the start of the line? IF yes --
Code:
echo "AAAAAP" | egrep '^[A-Z]+P'

# 3  
Old 05-18-2009
Thanks a lot!, works a charm

Last edited by Calypso; 05-18-2009 at 09:04 AM..
# 4  
Old 05-18-2009
please could you just explain why it only works with egrep and not the normal grep

also please could just confirm the following

^ means must start with pattern
+ means one or more occurence of pattern

Thanks again

Calypso
# 5  
Old 05-18-2009
Quote:
Originally Posted by Calypso
... why it only works with egrep and not the normal grep
...
That's because of that pesky "+" character, which means "one or more occurrence" and is an extended regex and hence supported by egrep (extended grep). Check the man page for egrep in your system.

The equivalent regex for this in grep would be:

Code:
$
$ echo "AAAAAP" | grep '^[A-Z][A-Z]*P'
AAAAAP
$

tyler_durden

Previous Thread | Next Thread
Test Your Knowledge in Computers #767
Difficulty: Medium
A victim cache is a cache used to hold blocks evicted from a CPU cache upon replacement.
True or False?

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Grep regex

Hi everyone, I'm looking for a grep command to match the following pattern from a file: <EGS>10234567<EGS> I used this following command to do this: grep -E '^<EGS>{8}<EGS>' test.txt In output I got: <EGS>10234567<EGS> Till now it work, but if I add something at the end of the line... (2 Replies)
Discussion started by: Arnaudh78
2 Replies

2. UNIX for Beginners Questions & Answers

Grep in regex

Hello guys, Here i am writing a script in bash to check for a valid URL from a file using regex This is my input file http://www.yahoo.commmmmm http://www.google.com https://www.gooogle.co www.test6.co.in www.gmail.com www.google.co htt://www.money.com http://eeeess.google.com... (2 Replies)
Discussion started by: Meeran Rizvi
2 Replies

3. Shell Programming and Scripting

Grep with regex containing one string but not the other

Hi to you all, I'm just struggling with a regex problem and I'm pretty sure that I'm missing sth obvious... :confused: I need a regex to feed my grep in order to find lines that contain one string but not the other. Here's the data example: 2015-04-08 19:04:55,926|xxxxxxxxxx| ... (11 Replies)
Discussion started by: stresing
11 Replies

4. Shell Programming and Scripting

grep -v and regex

How to match lines that don't contain a patern in regex it self, without using the -v option of grep? (15 Replies)
Discussion started by: vistastar
15 Replies

5. UNIX for Dummies Questions & Answers

| help | unix | grep (GNU grep) 2.5.1 | advanced regex syntax

Hello, I'm working on unix with grep (GNU grep) 2.5.1. I'm going through some of the newer regex syntax using Regular Expression Reference - Advanced Syntax a guide. ls -aLl /bin | grep "\(x\)" Which works, just highlights 'x' where ever, when ever. I'm trying to to get (?:) to work but... (4 Replies)
Discussion started by: MykC
4 Replies

6. Shell Programming and Scripting

grep and regex question

basically i have a csv i parse through. a user will supply me with a san switch he/she wants more info about... say the name is "pnj-sansw124" now i can grep out every connection to that switch w/o issue because this sans switch pnj-sansw124 has multiple slots 1-10. and it looks like this in the... (5 Replies)
Discussion started by: pupp
5 Replies

7. UNIX for Dummies Questions & Answers

Help with grep and regex

Hi all, I'm a beginner with linux, regex, grep, etc I am trying to get data out of a file that has about 13,000 lines in this format name - location I want to grep all the names out to one file and the locations to another so I can put them into a spreadsheet. Some have hyphenated... (14 Replies)
Discussion started by: raichlea
14 Replies

8. UNIX for Dummies Questions & Answers

grep with Regex help!

Hello everybody, I'd like to know how is it I should write a regex in unix to match a string not followed by another string (anywhere in the line). To be more specific, I want to find lines where "drop table" is found, but not followed anywhere in the line by the character "&". For... (3 Replies)
Discussion started by: mvalonso
3 Replies

9. Shell Programming and Scripting

grep regex problem

Hi, I am trying to do something with grep, but for some reason I just can't get it to to work. I am looking for find a match in the second field, the length must be 10 characters and end with 'abc'. The file is in this format: <int><tab><field2> I've tried a few patterns, some work,... (2 Replies)
Discussion started by: iceman
2 Replies

10. UNIX for Dummies Questions & Answers

use of regex on grep

having a look on the regex site I saw that characters can be search using hex values http://www.regular-expressions.info/characters.html So I try to use it whith grep to find a on a string (octal Decimal Hexa : 350 232 E8) but it doesn't work E.g. /usr/bin/echo '\0350' | egrep '\xE8' ... (0 Replies)
Discussion started by: solea
0 Replies

Featured Tech Videos