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

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6
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4answers
204 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?
6
votes
1answer
2k views

Removing leading zeros from DATE

I made an alias of the date command to display date in the following format: 2013.06.14.12.10.02 using this command: alias date = date +"%Y.%m.%d.%H.%M.%S" Everything works great, except I ...
6
votes
1answer
9k views

Only return the matched string in sed [duplicate]

Possible Duplicate: Extracting a regex matched with 'sed' without printing the surrounding characters How do I make this only print test: echo "atestb" | sed -n 's/\(test\)/\1/p'
6
votes
2answers
19k 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 != ...
6
votes
2answers
413 views

what is the meaning of this sed command: `;/@/{h;s/test/next/g;x;G}`?

sed -e 's/72;/72, next_val = 0x11111111;/;/@/{h;s/test/next/g;x;G}' fmt_vuln.c > fmt_vuln2.c could you tell me about what is the meaning of ;/@/{h;s/test/next/g;x;G}?
6
votes
2answers
2k views

Remove unknown unicode character from textfiles - sed, other bash/shell methods

I need to search and replace all occurences of an unknown character in some files having the same name. Opening such files with vi, I read <91> code for that character. Opening them with nano, I ...
6
votes
2answers
195 views

Regex `/pattern/g` and ed `:g/pattern/`: which came first, and why `g`?

The g option (e.g. s/pattern/replacement/g) for many tools that use regex-style pattern matching and the :g command in ed, ex, vi, and vim have pretty similar usage and meaning: match the given regex ...
6
votes
2answers
492 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 ...
6
votes
2answers
97 views

How come sed is so fast?

I thought about whether this question is suitable for SE or not, I hope you agree it is. Some time ago I asked on SE how to find text in files and leave the file with only the matching lines that ...
5
votes
4answers
1k views

How to append end of every line with the line itself

This is in file.txt: redcar bluecar greencar Im looking for ways to make it become: redcar redcar bluecar bluecar greencar greencar I've tried many ways using sed with no luck
5
votes
5answers
647 views

Sed: extending a string of numbers to a certain number of digits by padding with zeros

I'm currently trying to modify an echoed string of alphanumeric characters by piping it to sed. The area I'm interested in modifying is a block of numbers, which I would like to make 8 characters long ...
5
votes
7answers
823 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 ...
5
votes
4answers
479 views

Reduce the over use of files in text processing

Currently, I have a file (Results.txt) which has 27k rows. The file content is as below. 45008657 | A. | | Long | 0 49210987 | A. | ...
5
votes
3answers
501 views

Why does sed act differently depending on the output file?

If I run: cat messages.txt | sed -e 's/a/a/g' > messages.txt on one large file (2500+ lines) I find that the resulting file will only have about 900 lines after the command in cygwin and will ...
5
votes
6answers
810 views

Replace a character except last x occurences

I have a file that has a bunch of hostnames correlated with IPs that looks like this: x-cluster-front-1 192.168.1.2 x-cluster-front-2 192.158.1.10 y-cluster-back-1 10.1.11.99 y-cluster-back-2 ...
5
votes
3answers
482 views

Deleting Lines if there is a dot in the 5th Column

I have a file and I want to remove all the line if it has a dot in the 5th Column. Input File: sc2/80 20 . A C 80 PASS N=2 F=5;U=4 sc2/60 ...
5
votes
4answers
276 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 ...
5
votes
5answers
19k views

Multiline pattern match using sed, awk or grep

Is it possible to do a multiline pattern match using sed, awk or grep? Take for example, I would like to get all the lines between { and } So it should be able to match 1. {} 2. {.....} 3. ...
5
votes
2answers
292 views

How is the inplace modification of a file being done?

What does the "inplace" modification of a file e.g. via sed -i or perl -i mean? My question is about how this inplace modification is done. Is the file copied the modification is done in the copy and ...
5
votes
3answers
462 views

Is it possible to match multiple specific line numbers (not range) with sed?

Consider: echo -e "a\nb\nc\nd\ne\nf\ng\nh" | sed '3,5a test' This will match lines 3, 4 and 5. But I am trying to match only lines 3 and 5 (not 4). And append 'test' after them.
5
votes
4answers
359 views

reverse order of paragraphs in file

I have a file containing text in paragraphs (lines with text separated by one or more empty lines). I would like to reverse the order of paragraphs (i.e. last paragraph will become the first, ...), ...
5
votes
4answers
516 views

sed how to substitute when string has “http://” in it?

I have a file xx that has the following contents: @base_url = "http://dmstaffing-stage.herokuapp.com/" I want to use sed to eliminate this line (replace with nothing). I have used this sed ...
5
votes
2answers
4k views

How to replace a left parenthesis with sed?

I have to replace ( with some character in my file, and I can't do it. \( is used for grouping in sed and when I used \\( with sed, it treated it as \( character not as just (. It seems like a tricky ...
5
votes
4answers
226 views

How could I simplify this command to only use awk?

awk '/user/ {print $1 }' /etc/userdomains | sed 's/://' the format of /etc/userdomains is domain.tld: user otherdomain.tld: otheruser
5
votes
2answers
201 views

sed + how to delete the second character “.” from the line

how to delete the second character "." from the line what I have is this ( but its remove the first "." from output uname -r | sed s'/\./ /' 2 6.18-164.2.1.el5PAE while I need the following ...
5
votes
2answers
505 views

Does `sed` exist in all *nixes?

My application will be running on all versions of Unix-based OS, say, Linux, MacOS, HP-UX, Sun Solaris , OSX, etc. I'm using the following sed command in a common place to delete the string matched ...
5
votes
4answers
262 views

Is there a difference between read, head -1, and sed 1q?

The following commands seem to be roughly equivalent: read varname varname=$(head -1) varname=$(sed 1q) One difference is that read is a shell builtin while head and sed aren't. Besides that, is ...
5
votes
4answers
2k views

How to add a carriage return before every newline?

I have a file that only uses \n for new lines, but I need it to have \r\n for each new line. How can I do this? For example, I solved it in Vim using :%s/\n/\r\n/g, but I would like to use a script ...
5
votes
4answers
262 views

sed ranges aren't always able to match only one line

Consider the following range: 1,/pattern/. If pattern matches on the first line, the range matches for the whole file: $ cat 1.sh #!/usr/bin/env bash set -eu seq 1 4 | sed -rn '1,/'"$1"'/p' $ ./1.sh ...
5
votes
3answers
3k views

How can sed output be formatted like printf's formatted printing?

Can sed replace text with a string formatted like printf's formatted printing? The following sed command replaces a line starting with the current value of "$domain" with several values specified in ...
5
votes
3answers
611 views

emulate tail with sed

I have a mini-system with only limited number of binaries (bash,cp,cat,sed, ...). I don't have tail command, and I am wondering if I could emulate tail functionality with sed cat foo.txt | tail -n 10 ...
5
votes
4answers
992 views

sed behaves different on FreeBSD and on Linux?

I use both Linux and FreeBSD (specifically, I use Debian Linux and PC-BSD), and I found something weird about sed. I frequently need to convert "tab separated values" files to "comma separated ...
5
votes
1answer
2k views

Replacing multiple lines in sed or awk [closed]

I'm trying to use sed or awk to replace 5 lines in a smb file but I just don't have any idea how to deal with the newlines.
5
votes
4answers
225 views

How to replace m part of Lines with n part of Lines?

I have a file "test" like this: RewiteEngine On RewriteCond %{REMOTE_ADDR} !^192\.168\.1\.7$ [NC] RewriteCond %{REMOTE_ADDR} !^192\.168\.1\.8$ [NC] RewriteCond %{REMOTE_ADDR} ...
5
votes
6answers
2k views

How to match exact string using `sed`? But not the part of it.?

I have a input file FILE1.TXT as below. 11 id1 12 13 AGE = 20 14 NAME = NAME1 15 16 id2 17 18 AGE = 30 19 NAME = NAME2 . . . 110 idXYZ 111 112 AGE = AGEXYZ 113 NAME = ...
5
votes
4answers
11k 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 ...
5
votes
7answers
8k views

How to print all lines after a match up to the end of the file?

Input file1 is: dog 123 4335 cat 13123 23424 deer 2131 213132 bear 2313 21313 I give the match the pattern from in other file ( like dog 123 4335 from file2). I match the pattern of the line ...
5
votes
3answers
3k 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 ...
5
votes
3answers
540 views

Extracting fixed width records with no delimiter from a single line

I need to extract strings of text from a single file containing one very long line of text with no delimiters. Using the sample line below, these are the following known facts: ...
5
votes
2answers
3k views

Single command taking two strings to extract string between them, like 'tr' (without expressions)

Saw here a way to use sed to get text between two other strings in a line, like: sed 's/.*starting_text\(.*\)ending_text.*/\1/' but I'd like a simple command (like tr, but for string extraction) ...
5
votes
3answers
79 views

How to change a set of characters between delimiters for exact line?

I am trying to write a script for changing user password in dovecot user database and I can't understand how to replace a set of characters between delimiters for exact lines with sed. Please check ...
5
votes
3answers
248 views

Replace multiple strings in a single pass

I'm looking for a way to replace placeholder strings in a template file with concrete values, with common Unix tools (bash, sed, awk, maybe perl). It is important that the replacement is done in a ...
5
votes
2answers
174 views

How to use shell to derive an IPv6 address from a MAC address?

We know that we can use the MAC address to create an interface identifier, e.g. for a link-local IPv6 address which should be unique in the Network. The image shows the way to do this: My ...
5
votes
3answers
186 views

Extracting data from complex file structure

I have a txt file that is a dump from a database, that contains one entry per line. The structure is like this: 1500 29/03/2010 18 02 09 47 17 45 28.248 0 0.01 130 12.721 7908 298,809 YES ...
5
votes
2answers
111 views

Adding corresponding Numbers in a Range

I have a dataset with 30000 lines. I want to add all the corresponding values (i.e. Column 2) between the range 0-50 and then 50.1-100 and then 100.1-150 etc. (presented in column 1), and this ...
5
votes
3answers
4k views

Filter a .CSV file based on the 5th column values of a file and print those records into a new file

I have a .CSV file with the below format: "column 1","column 2","column 3","column 4","column 5","column 6","column 7","column 8","column 9","column 10 "12310","42324564756","a simple string with a , ...
5
votes
4answers
4k views

SED : Delete 4 line above and below 5 line after pattern match

I have Hugh file with following details : define host{ use generic-host ; Name of host template to use host_name ServerA_172.29.16.102 ...
5
votes
1answer
226 views

Execute a command within 'sed'

I have a list of random memory addresses saved in a text file, and I need to sed them out, decode them, and save them back to my file. However, the decoding operation I'm trying to perform is handled ...
5
votes
3answers
493 views

Gedit or an other non-commandline editor with the ability to spell-check two languages at the same time

I'm searching for an editor with the ability to spell-check two languages at the same time (German and English). Gedit can't do it out of the box. But I want to use Gedit. It should be possible by ...
5
votes
2answers
193 views

Comment all lines from last commented line to line with 'foo'

Consider a text file users.txt: #alice #bob charlie dotan eric I need to comment everything from (exclusive) the last commented line until (inclusive) dotan. This is the result: #alice #bob ...