CODEWITHSUNDEEP
regexshellunixsh
Sheharyar Irfan
Sheharyar Irfan

Reputation: 33

Egrep regex end of line not matching properly with $

My pattern needs to have three words where there is a single SPACE character separating the three tokens in each line.

for example 

inherit class3 class4
inherit class35 class5
implement class3 interface1
aggregate class3 class5

My code is egrep -i "^[0-9a-z]+\ [0-9a-z]+\ [0-9a-z]+$" "$input2"

This still does not match it properly and outputs nothing with $ at the end, but if i remove the $, it outputs the lines having more than 3 tokens in each line. I've been trying to make it work perfectly for a really long time but its not working. Thanks.

Test file has this

d d d d
 dfsdfg afegsdfh asfg
efgfah afgadfg adfsg 
awg  awg wga
wrhg warg  wrgrw
awdg afsg
sdg

asdg asdg asdg asdg

Upvotes: 0

Views: 423

Answers (4)

beroe
beroe

Reputation: 12316

Your test file doesn't seem to have any patterns that exactly match the search... there is a space at the end of the one line that would match.

enter image description here

To solve, add some optional spaces in your search with *...

Upvotes: 1

sdanzig
sdanzig

Reputation: 4500

Given the test data, no lines will match the regex. It is behaving as it should. You might think it will match the third line, but it can't because there's a trailing space, so the third token is not immediately followed by the end of line.

When you remove the end of line character from the regex pattern, it indeed does not have this constraint, so, as long as the line begins with three tokens separated by a space, it will be matched. Therefore, the lines, as described by the asker, would print out.

Upvotes: 1

Ashish Gaur
Ashish Gaur

Reputation: 2050

Try this:

 egrep -i "^\ *[0-9a-z]+\ [0-9a-z]+\ [0-9a-z]+\ *$"

The command you tried was not working because it doesn't capture the cases when there are spaces in the beginning or end.

Upvotes: 0

Tom Ron
Tom Ron

Reputation: 6181

$ is a a regex symbol for end of line. Therefore if you want something to end with $ you should you backslash (as you use near the brackets) - \$. As I see it your command should actually end with \$$

Upvotes: 0

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