sed is a command-line stream editor for filtering and transforming text.

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8
votes
7answers
467 views

Swapping an unlimited number of columns

I have a file with columns. See below for an example: a b c ... z 1 2 3 ... 26 I'd like to swap all columns where the 1st becomes the last, the second becomes the one before last...etc.. z y x ...
8
votes
5answers
2k views

Convert file contents to lower case

I have temp file with some lower-case and upper-case contents. Input Contents of my temp file: hi Jigar GANDHI jiga I want to convert all upper to lower. Command I tried the following command: ...
8
votes
4answers
2k views

How do I write a sed one-liner to add a character after every third character?

So, I have a string that looks like this: AUGGCCAUGGCGCCCAGAACUGAGAUCAAUAGUACCCGUAUUAACGGGUGA And I want to split the string into 3-character chunks delimited by a '+' sign. ...
8
votes
6answers
505 views

How to append Line to previous Line?

I have a Log file which need to be parsed and analysed. File contains something similar like below: File: 20141101 server contain dump 20141101 server contain nothing {uekdmsam ikdas jwdjamc ...
8
votes
6answers
2k views

Delete lines beginning with #

How do I delete lines beginning with a #, given that there can be whitespace on the left and right of the #? # Master socket provides access to userdb information. It's typically
8
votes
2answers
15k views

How to replace a string with a string containing slash with sed?

i am looking for a way to replace a string in a file with a string that contains a slash by using sed. connect="192.168.100.61/foo" srcText="foo.bar=XPLACEHOLDERX" echo $srcText | sed ...
8
votes
5answers
5k views

How to remove multiple blank lines from a file?

I have some text-files I use to take notes in - just plain text, usually just using cat >> file. Occasionally I use a blank line or two (just return - the new-line character) to specify a new ...
8
votes
3answers
2k views

Remove only the commas present within the double quotes

In a text file, I want to remove , (commas) and also the " (quotes) (only if the double quotes contains numbers seperated by commas). 56,72,"12,34,54",x,y,"foo,a,b,bar" Expected ouput ...
8
votes
5answers
2k views

How to delete line if longer than XY?

How can i delete a line if it is longer than e.g.: 2048 chars?
8
votes
7answers
537 views

How can I “merge” patterns in a single line?

I am doing grep and sed and I get 2 lines of a file that I am interested in. How can I get these lines in a single line ending with the new line character? Now I am getting: pattern1 pattern2 ...
8
votes
4answers
10k views

grep — removing text after delimiter token

I have a file in which I need to eliminate everything after the first ; on every line. So a file like this: sdfsdsdf; fsdfsddf;sdfsd; Will result in this: sdfsdsdf fsdfsddf I have looked into ...
8
votes
2answers
18k views

How to insert text after a certain string in a file?

Right now I'm using echo "Hello World" >> file.txt to append some text to a file but I also need to add text below a certain string let's say "[option]", is it possible with sed? EG: Input ...
8
votes
6answers
1k views

How to get multiple lines out of a file by a regex?

How to get multiple lines out of a file by a regex? I often would like to get multiple lines / modify multiple lines by a regex. A example case: I am trying to read part of an XML/SGML file (they ...
8
votes
3answers
6k views

How do I grep without leading whitespaces?

I'm greping through a large codebase, and leading whitespaces and tabulation seem to be quite annoying. Is there any way to get rid of it? grep -R "something" ./ E.g, instead of: foo/bar.cpp: ...
8
votes
2answers
1k views

Deleting all C comments with sed

I am trying to write a script that will delete all comments and everything in between inside C files in my current directory. I've been using sed, and this is what I have so far: sed -i '/ * [^()] ...
8
votes
4answers
6k views

Remove files older than 5 days in UNIX (date in file name, not timestamp)

I want to delete log files which are older than 5 days from a directory. But deletion should not be based on the timestamp of file. It should be based on the name of file. For Example todays date is ...
8
votes
1answer
287 views

regarding portable sed -e… d b or ! b?

In this edit Stéphane Chazelas POSIXifies (again) my sed formatting by inserting an -expression break and another -expression statement. Now, I might just ask him why in the comments, I suppose, but ...
7
votes
10answers
5k views

Decoding URL encoding (percent encoding)

I want to decode URL encoding, is there any built-in tool for doing this or could anyone provide me with a sed code that will do this? I did search a bit through unix.stackexchange.com and on the ...
7
votes
10answers
2k views

What's a good way to filter a text file to remove empty lines?

I have a .csv file (on a mac) that has a bunch of empty lines, e.g.: "1", "2", "lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum ...
7
votes
3answers
1k views

How to remove a specific character in a string but only if there are no numbers in that line in Linux

I've been stumped with this seemingly simple-to-fix problem.. well, for a while. Here's example output from the file I need to edit: $cat file George Washington Geneva Convention 123,281,029 USD ...
7
votes
4answers
6k views

sed on OSX insert at a certain line

So I've been using 'sed' on linux for a while, but have had a bit of difficulty trying to use it on OSX since 'POSIX sed' and 'GNU sed' have so many little differences. Currently I'm struggling with ...
7
votes
3answers
9k views

How to sed only that lines that contains given string?

INPUT: Select ASDF 325 sdfg sdflk lk Select TRG 46sdg rasdftz fsgs 45 Select ASDF 6ffg sdfg 4456 sdrg OUTPUT: Select ASDF 325 XXXX sdflk lk Select TRG 46sdg rasdftz fsgs 45 Select ASDF 6ffg XXXX ...
7
votes
4answers
4k views

How to embed a shell command into a sed expression?

I have a text file with the following format: keyword value keyword value ... Where keyword is a single word and value is everything else until the end of line. I want to read the file from a shell ...
7
votes
4answers
227 views

Matching and pasting to line

So I have 2 very big text files, consisting of lines like so: First: Robert:Dillain:Other:Other:Other Julian:Brude:Other:Other:Other Megan:Flikk:Other:Other:Other Samantha:Minot:Other:Other:Other ...
7
votes
4answers
742 views

How to split long sed expression into multiple lines?

sed 's/[long1][long2]/[long3][long4]/' file.txt I would like to split this command onto multiple lines - f.x. something like this: sed 's/ [long1] [long2] / [long3] [long4] /' ...
7
votes
4answers
11k views

Delete range of lines above pattern with sed (or awk)

I have the following code that will remove lines with the pattern banana and 2 lines after it: sed '/banana/I,+2 d' file So far, so good! But I need it to remove 2 lines before banana, but I can't ...
7
votes
8answers
15k views

Using sed to convert newlines into spaces

Say I have a shell variable $string that holds some text with several newlines, e.g.: string="this is a test" I would like to convert this string into a new string new_string where all line breaks ...
7
votes
4answers
16k views

Text between two tags

I wanna retrieve whatever is between these two tags – <tr> </tr> – from an html doc. Now I don't have any specific html requirements that would warrant for an html parser. I just plain ...
7
votes
4answers
454 views

Replace \n by a newline in sed portably

I'm so confused with GNU sed, POSIX sed, and BSD sed's myriad of options. How do I replace literal \n with the newline character using these three sed types?
7
votes
3answers
3k views

How can I instruct BSD sed to interpret escape sequences like \n and \t?

I have a sed replacement command that I would like to be compatible with BSD sed as well as GNU sed. Extended regular expressions are not an issue as I do not need them in this case. My primary ...
7
votes
2answers
24k views

Removing all spaces, tabs, newlines, etc from a variable?

This is the error I am getting and it's failing because of a variable whose value is supposed to be 2 (I am getting this using a select * from tabel). I am getting spaces in that variable. + 0 != ...
7
votes
3answers
1k views

Print a line only if the next line does NOT contain a particular match

I am trying to search a log file for logged activities that did not complete. For example, I log a "Starting activity for ID 1234..." and if successful, the next line will be "Activity 1234 ...
7
votes
1answer
324 views

Change date “July 29th, 2011” to “20110729”

I have lots of HTML files contains date with format July 29th, 2011 I want to change date format July 29th, 2011 to 20110729, December 9th, 2010 to 20101209, etc. I think sed may works but still ...
7
votes
2answers
610 views

Which sed version is not GNU sed 4.0?

I'm trying to figure out which version of sed that I've got on BusyBox 1.18.3. The --version output is cryptic. $ sed --version This is not GNU sed version 4.0 The following code is from the ...
7
votes
4answers
11k views

Copy/rename multiple files using regular expression (shell script)

I have a collection of files matching a pattern such as 'assignment02.cc', 'assignment02.h', 'assignment02.txt', etc. I would like to copy/rename these files into 'assignment03.cc', 'assignment03.h', ...
7
votes
1answer
784 views

How do you save a complex regex for multiple reuse in sed?

In using sed, I often create rather complicated and intricate regexes that I need to match twice in a file. Is there a way for me to save this regex and just reference it twice? Maybe something that ...
7
votes
1answer
1k views

Is there an option to make sed fail if pattern not found?

I need to find and replace some patterns in some files, but I need it to return 1 or something if a pattern is not found. Can I do this with sed alone or do I need to check whether the pattern exists ...
6
votes
6answers
13k views

How to use the sed command to only show the first column and last column in a text file

I need some help to figure out how to use the sed command to only show the first column and last column in a text file. Here is what I have so far for column 1: cat logfile | sed 's/\|/ /'|awk ...
6
votes
8answers
7k views

Can sed remove 'double' newline characters?

I have a document with a lot of empty lines. How can I remove them when there are 2 or more together. I tried sed "s/\n\n//" file but it didn't work. No error.
6
votes
4answers
804 views

Using sed to add a URL to the start of every line

I have the URL (see below) of a certain web page that lists many different versions of a software package. URL=http://ftp.gnu.org/gnu/wget/ The following one-liner gets me the latest version tar ...
6
votes
5answers
270 views

Get filesystem name and usage with `df -h`

df -h | grep test | sed -e 's/*%.^ //g;s/.*[ ^I]//' Output: /test /test/drv0 /test/drv1 df -h | grep test | cut -d '%' -f1 | sed -e 's/*%.^ //g;s/.*[ ^I]//' Output: 10 20 15 I want to ...
6
votes
5answers
520 views

What's wrong with this sed expression?

$ echo "104_Fri" | sed 's/^\([0-9]+\)_\([A-Za-z]+\)$/\1;\2/' 104_Fri I would like to match the digits at the beginning and the letters at the end - each as a group. Afterwards I want to output the ...
6
votes
8answers
2k views

Grep rest of line…after match

I have a file containing only two lines, with the following structure: $ cat /tmp/pwpower.log 000D6F0000D34227, -114.10 000D6F0001A405C4, -130.09 The values are power values of my solar plant. ...
6
votes
4answers
11k views

Processing bash variable with sed

Been banging my head off a wall on this bash variable LATLNG contains a latitude & longitude value in brackets like so (53.3096,-6.28396) I want to parse these into a variable called LAT and ...
6
votes
5answers
252 views

Strategy to extract movies's name from this ununiform dataset?

I am working on a movie database problem to improve regular expressions, this is the problem I'm running into. My dataset looks like this: Movie Name (variable space and tabs) year Movie1(can ...
6
votes
4answers
583 views

how to remove ctrl F in unix file

While editing a unix file I'm getting data as below in vi editor. MGW:^FVMG107 MGW:^FVMG113 MGW:^FVMG108 MGW:^FVMG103 where in above data ^F is not viewable in cat command. I have tried dos2unix ...
6
votes
2answers
4k views

sed one-liner to delete any line that does not contain lowercase letters

So, basically THIS LINE WOULD BE DELETED and (THIS LINE WOULD ALSO BE DELETED) but Indeed, THIS LINE WOULD NOT
6
votes
4answers
1k views

Replace a string containing newline characters

With the bash shell, in a file with rows like the following ones first "line" <second>line and so on I would like to replace one or more occurrences of "line"\n<second> with other ...
6
votes
3answers
5k views

What is the purpose of -e in sed command?

I can't find any documentation about the sed -e switch, for simple replace, do I need it? e.g. sed 's/foo/bar/' VS sed -e 's/foo/bar/'
6
votes
3answers
232 views

sed with multiple expression for in-place arguement

I am trying to replace multiple words in file by using sed -i #expression1 #expression2 file Something 123 item1 Something 456 item2 Something 768 item3 Something 353 item4 Output (Desired) ...