Sponsored Content
Top Forums Shell Programming and Scripting How to remove newline character if it is the only character in the entire file.? Post 303029514 by MadeInGermany on Monday 28th of January 2019 09:28:16 AM
Old 01-28-2019
In contrast to wc, grep with -l or -q option stops reading the input when a match has occurred.
In this case a
Code:
grep -q . file

(stop if any character is met) seems sufficient.
Because grep returns an exit status it becomes quite simple:
Code:
file=myfile.log
grep -q . "$file" || >"$file"

Note that -q is not portable. If this is an issue, use the -l option and suppress output.
Code:
file=myfile.log
grep -l . "$file" >/dev/null || >"$file"


Last edited by MadeInGermany; 01-28-2019 at 10:38 AM..
These 3 Users Gave Thanks to MadeInGermany For This Post:
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to remove a newline character at the end of filename

Hi All, I have named a file with current date,time and year as follows: month=`date | awk '{print $2}'` date=`date | awk '{print $3}'` year=`date | awk '{print $6}'` time=`date +%Hh_%Mm_%Ss'` filename="test_"$month"_"$date"_"$year"_"$time".txt" > $filename The file is created with a... (2 Replies)
Discussion started by: amio
2 Replies

2. Shell Programming and Scripting

To remove the newline character while appending into a file

Hi All, We append the output of a file's size in a file. But a newline character is appended after the variable. Pls help how to clear this. filesize=`ls -l test.txt | awk `{print $5}'` echo File size of test.txt is $filesize bytes >> logfile.txt The output we got is, File size of... (4 Replies)
Discussion started by: amio
4 Replies

3. Shell Programming and Scripting

Remove newline character conditionally

Hi All, I have 5000 records like this Request_id|Type|Status|Priority|Ticket Submitted Date and Time|Actual Resolved Date and Time|Current Ticket Owner Group|Case final Ticket Owner Group|Customer Severity|Reported Symptom/Request|Component|Hot Topic|Reason for Missed SLA|Current Ticket... (2 Replies)
Discussion started by: j_53933
2 Replies

4. Shell Programming and Scripting

any savant ? using AWK/SED to remove newline character between two strings : conditional removal

I'd like to remove (do a pattern or precise replacement - this I can handle in SED using Regex ) ---AFTER THE 1ST Occurrence ( i.e. on the 2nd occurrence - from the 2nd to fourth occurance ) of a specific string : type 1 -- After the 1st occurrence of 1 string1 till the 1st occurrence of... (4 Replies)
Discussion started by: sieger007
4 Replies

5. Shell Programming and Scripting

Remove \n <newline> character inside the records.

Hi, In my file, I have '\n' characters inside a single record. Because of this, a single records appears in many lines and looks like multiple records. In the below file. File 1 ==== 1,nmae,lctn,da\n t 2,ghjik,o\n ut,de\n fk Expected output after the \n removed File 2 =====... (5 Replies)
Discussion started by: machomaddy
5 Replies

6. Shell Programming and Scripting

Remove newline character or join the broken record

Hi, I have a very huge file, around 1GB of data. I want to remove the newline characters in the file but not preceded by the original end delimiter {} sample data will look like this 1234567 abcd{} 1234sssss as67 abcd{} 12dsad3dad 4sdad567 abcdsadd{} this should look like this... (6 Replies)
Discussion started by: ratheeshjulk
6 Replies

7. Shell Programming and Scripting

How to check newline character in file?

Hi All, I have file with only one record,always be only one record. as like below. if that line contains newline end of the line..no need to add, if not just add the new line character. END OF FILE. ROW COUNT: 7 Please help me.. Thanks, (9 Replies)
Discussion started by: bmk
9 Replies

8. Shell Programming and Scripting

Remove newline character between two delimiters

hi i am having delimited .dat file having content like below. test.dat(5 line of records) ====== PT2~Stag~Pt2 Stag Test. Updated~PT2 S T~Area~~UNCEF R20~~2012-05-24 ~2014-05-24~~ PT2~Stag y~Pt2 Stag Test. Updated~PT2 S T~Area~METR~~~2012-05-24~2014-05-24~~test PT2~Pt2 Stag Test~~PT2 S... (4 Replies)
Discussion started by: sushine11
4 Replies

9. Shell Programming and Scripting

Remove last newline character..

Hi all.. I have a text file which looks like below: abcd efgh ijkl (blank space) I need to remove only the last (blank space) from the file. When I try wc -l the file name,the number of lines coming is 3 only, however blank space is there in the file. I have tried options like... (14 Replies)
Discussion started by: Sathya83aa
14 Replies

10. UNIX for Beginners Questions & Answers

Remove newline character from column spread over multiple lines in a file

Hi, I came across one issue recently where output from one of the columns of the table from where i am creating input file has newline characters hence, record in the file is spread over multiple lines. Fields in the file are separated by pipe (|) delimiter. As header will never have newline... (4 Replies)
Discussion started by: Prathmesh
4 Replies
ZGREP(1)						      General Commands Manual							  ZGREP(1)

NAME
zgrep - search possibly compressed files for a regular expression SYNOPSIS
zgrep [ grep_options ] [ -e ] pattern filename... DESCRIPTION
Zgrep invokes grep on compressed or gzipped files. These grep options will cause zgrep to terminate with an error code: (-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*). All other options specified are passed directly to grep. If no file is specified, then the standard input is decompressed if necessary and fed to grep. Otherwise the given files are uncompressed if necessary and fed to grep. If the GREP environment variable is set, zgrep uses it as the grep program to be invoked. EXIT CODE
2 - An option that is not supported was specified. AUTHOR
Charles Levert (charles@comm.polymtl.ca) SEE ALSO
grep(1), gzexe(1), gzip(1), zdiff(1), zforce(1), zmore(1), znew(1) ZGREP(1)
All times are GMT -4. The time now is 11:22 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy