Removing the following characters after a pattern in a text file in Unix

Question

I have a text file which has the following lines:

Customer Details Report - A03_2014-01-04_09-00-09.txt
DemandResetFailureReport_2014-01-04_11-00-08.txt
ExcessiveMissingReadsReport_2014-01-04_09-00-11.txt
LipaBillingSumCheckReport_2014-01-04_11-00-08.txt
LipaUsageBillingReport_2014-01-04_12-55-06.txt

I want to run a command in UNIX (say, sed) which will edit the contents of the text file as:

Customer Details Report 
DemandResetFailureReport
ExcessiveMissingReadsReport
LipaBillingSumCheckReport
LipaUsageBillingReport

I came across some commands such as sed '/^pattern/ d' to remove all lines after pattern. But where is the text file specified in the command?

BTW `sed '/^pattern/d'` removes all lines having the word `pattern` at the beginning. If you use a regex instead of `^pattern`, it removes all lines matching that pattern. — Palec, Jan 06 '14 at 14:57

fedorqui · Answer 1 · 2014-01-06T15:00:06.903

2

With awk you can set - and _ as field separator (-F[-_]) and print the first block ({print $1}):

$ awk -F"[-_]" '{print $1}' file
Customer Details Report 
DemandResetFailureReport
ExcessiveMissingReadsReport
LipaBillingSumCheckReport
LipaUsageBillingReport

edited Jan 06 '14 at 15:00

answered Jan 06 '14 at 14:41

fedorqui

275,237
103
548
598

1

OP doesn't want to have `_2014` in output. – Kent Jan 06 '14 at 14:45
Solved, just left the `awk` version. Thanks, Kent 2014 :) – fedorqui Jan 06 '14 at 14:49
better make sure you quote the -F pattern. If you have a file named "_", or if you have the nullglob option enabled, you're in trouble. – glenn jackman Jan 06 '14 at 15:00

score 2 · Answer 2 · answered Jan 06 '14 at 14:44

2

grep -o '^[^-_]*'

outputs:

Customer Details Report 
DemandResetFailureReport
ExcessiveMissingReadsReport
LipaBillingSumCheckReport
LipaUsageBillingReport

answered Jan 06 '14 at 14:44

Kent

189,393
32
233
301

score 1 · Answer 3 · edited May 23 '17 at 10:25

I always use perl -pi, as follows:

$ perl -pi -e 's/[-_].*//' file
$ cat file
Customer Details Report 
DemandResetFailureReport
ExcessiveMissingReadsReport
LipaBillingSumCheckReport
LipaUsageBillingReport

If a backup of the original is needed, specify a suffix for the backup file, for example:

$ perl -pi.bak -e 's/[-_].*//' file

See also the following topic on editing files in place: sed edit file in place

score 0 · Answer 4 · edited May 23 '17 at 11:56

0

I would suggest using sed -i 's/[-_].*//' file.txt. Your text file (file.txt) must be passed as argument (I chose that way) or on standard input (sed 's/[-_].*//' < file.txt > file2.txt), but that way you could not edit it in-place (-i). Be sure not to use sed … <file.txt >file.txt as that will delete your file.txt contents.

edited May 23 '17 at 11:56

Community

1
1

answered Jan 06 '14 at 14:50

Palec

12,743
8
69
138

score 0 · Answer 5 · answered Jan 06 '14 at 15:32

0

This might work for you (GNU sed):

sed -ri 's/( -|_).*//' file

answered Jan 06 '14 at 15:32

potong

55,640
6
51
83

score 0 · Answer 6 · answered Jan 06 '14 at 19:17

0

Another awk

awk '{sub(/[-_].*/,x)}1' file
Customer Details Report
DemandResetFailureReport
ExcessiveMissingReadsReport
LipaBillingSumCheckReport
LipaUsageBillingReport

This removes what you does not want and print the rest.

answered Jan 06 '14 at 19:17

Jotne

40,548
12
51
55

Removing the following characters after a pattern in a text file in Unix

6 Answers6