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

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35
votes
2answers
48k views

How can I replace a string in a file(s)?

Replacing strings in files based on certain search criteria is a very common task. How can I replace string foo with bar in all files in the current directory? do the same recursively for sub ...
4
votes
1answer
147 views

How to ensure that string interpolated into `sed` substitution escapes all metachars

I have a script that reads a text stream and generates a file of sed commands that is later run with sed -f. The generated sed commands are like: ...
7
votes
2answers
11k views

Extracting a regex matched with 'sed' without printing the surrounding characters

To all the 'sed' doctors out there: I have a seemingly trivial 'sed' question to which I have not been able to find a solution. How can you get 'sed' to exctract a regular expression it has matched ...
14
votes
7answers
2k views

How can I prepend a tag to the beginning of several files?

I need to add PHP tags surrounding a file. It's easy to append them using find . -exec echo "?>" >> '{}' \; but how can I prepend the tag <?php?
11
votes
5answers
12k views

Remove comma between the quotes only in a comma delimited file

I have a input file delimited with commas (,). There are some fields enclosed in double quotes that are having a comma in them. Here is the sample row 123,"ABC, DEV 23",345,534.202,NAME I need to ...
16
votes
5answers
23k views

How to manipulate a CSV file with sed or awk?

How can I do the following to a CSV file using sed or awk? Delete a column Duplicate a column Move a column I have a big table with over 200 rows, and I'm not that familiar with sed.
6
votes
4answers
13k 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
3answers
665 views

How do I stop sed from adding extra newline characters

I am running the following 2 sed commands. The first one adds newline characters where I want them, the second also adds newline characters where I want them, BUT also adds an extra one at the end of ...
6
votes
4answers
16k views

Can sed replace new line characters?

Is there an issue with sed and new line character? I have a file test.txt with the following contents aaaaa bbbbb ccccc ddddd The following does not work: sed -r -i 's/\n/,/g' test.txt ...
4
votes
2answers
9k views

sed one-liner to delete everything between a pair of brackets?

I am working with some text that is full of stuff between brackets [] that I don't want. Since I can delete the brackets myself, I don't need the one-liner to do that for me, but I do need a one-liner ...
3
votes
2answers
5k views

Show only text between 2 matching pattern

I'm going to submit form using cURL, where some of the contents is come from other file, selected using sed If param1 is line matching pattern from other file using sed, below command will works ...
2
votes
3answers
4k views

Using a reference to a bash string variable in sed

I'm a relative Linux novice. Suppose that I have a text file a.txt that contains the following text: A B C Now, if I want to change the text on line 2 (which contains B), I can use the following ...
13
votes
6answers
981 views

How to achieve portability with sed -i (in-place editing)?

I'm writing shell scripts for my server, which is a shared hosting running FreeBSD. I also want to be able to test them locally, on my PC running Linux. Hence, I'm trying to write them in a portable ...
10
votes
3answers
11k views

Replace string with contents of a file using sed

I have two different files: File1 /home/user1/ /home/user2/bin /home/user1/a/b/c File2 <TEXT1> <TEXT2> I want to replace the <TEXT1> of File2 with the contents of File1 ...
4
votes
2answers
342 views

Why do I need to escape regex characters in sed to be interpreted as regex characters?

It seems e.g. cat sed_data.txt | sed 's/\b[0-9]\{3\}\b/NUMBER/g' that I must escape characters to form a regular expression. In this case I had to escape braces in order to be interpreted as a number ...
4
votes
3answers
2k views

Show lines matching a pattern and the 4 lines before each

For example, from this file: CREATE SYNONYM I801XS07 FOR I8010.I801XT07 * ERROR at line 1: ORA-00955: name is already used by an existing object CREATE SYNONYM I801XS07 FOR ...
2
votes
2answers
3k views

Comparing two files using Unix and Awk

I need to compare two files, File1 and File2 (Separated by space) using 4 fields (Field 1, 2, 4 and 5 of File 1 with field1, 2, 4 and 5 of File2). Logic: If column 1, 2 and 4 of File 1 matches with ...
5
votes
3answers
544 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 ...
1
vote
1answer
53 views

How to nest global matches with sed?

If I do: sed 's/match/replace/g' I know that sed will substitute replace for every occurrence of match on a line. But what if...? echo "match <please dont match this?>" | sed ...
33
votes
3answers
60k views

What characters do I need to escape when using sed in a sh script?

Take the following script: #!/bin/sh sed 's/(127\.0\.1\.1)\s/\1/' [some file] If I try to run this in sh (dash here), it'll fail because of the parentheses, which need to be escaped. But I don't ...
12
votes
4answers
17k views

Remove line containing certain string and the following line

I use this cat foo.txt | sed '/bar/d' to remove lines containing the string 'bar' in the file. I would like however to remove those lines and the line directly after it. Preferably in sed, awk or ...
11
votes
2answers
43k views

Return only the portion of a line after a matching pattern

So pulling open a file with cat and then using grep to get matching lines only gets me so far when I am working with the particular log set that I am dealing with. It need a way to match lines to a ...
12
votes
2answers
3k views

Differences between sed on Mac OSX and other “standard” sed?

I am having some issues in using an answer provided on this site for this question about a sed command to replace a blank line with two other lines of content, and it was brought up if the sed command ...
12
votes
4answers
2k views

Replacing Multiple blank lines with a single blank line in vim / sed

Question more or less says it all. I'm aware that /^$/d will remove all blank lines, but I can't see how to say 'replace two or more blank lines with a single blank line' Any ideas?
5
votes
1answer
1k views

Find all lines between a line matching a pattern and a line matching another pattern

i want to start grepping from the lines that has "CK" at the end of line and stop grepping when the line has "D" at the end. I tried grep "$CK" "$D" file..txt , but it didnt work. Input: kkkkkkkkkkk ...
2
votes
5answers
266 views

Can the string “abcedf” be matched to string “bafcde” in a single line command?

I am planning to implement an indexing structure in my program. For example, if I have 100 rows in the table, I will number these rows from 1 to 100 in another column by appending an _ to the end of ...
2
votes
6answers
4k views

Repeat each line multiple times

Would like to have each line in a file repeated a fixed number of times. e.g. have each line repeated four times: a b c becomes: a a a a b b b b c c c c I've done some searching, and there are ...
8
votes
5answers
556 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: ...
4
votes
2answers
4k views

Sed: replacing digits

I am trying to write some install scripts for when I install/upgrade Ubuntu. I'm having trouble with fixing logrotate.d: /var/log/ufw.log { rotate 7 weekly missingok notifempty compress delaycompress ...
7
votes
0answers
247 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 ...
5
votes
1answer
283 views

Variable in sed

I have a file that contains filenames with absolute path. In the middle of that path, is a variable directory, whenever I hard code the variable part, it works fine, but when I replace it with the ...
4
votes
3answers
832 views

Delete the matching line and several more from a file

I have a text file called file_a.txt. My first command is grep -A 12 ".production =" file_a.txt The output is a few block. Each block of string contains 13 rows I specifically want to delete all ...
3
votes
3answers
259 views

Rearrange text file by prepending data rows with header row

I have a file whose content looks like this: 2009 150 0 0 0 0000 75.316 0.0400390625 0.00007 0.00000 0.8980 76.216 0.0400390625 0.00007 1.00000 0.9046 77.217 0.0400390625 ...
3
votes
4answers
427 views

Piping paths with different types of quotes for slash substitution

I would like to use sed to convert a path with backslashes to the same path with forward slashes: E.g. I would like to pipe \\path\to\file\ and obtain /path/to/file None of the following commands ...
3
votes
2answers
1k views

Insert a multiline string into another string

I need to insert lines into an xml file : Insert <one> </one> into <tags> </tags> To obtain <tags> <one> </one> </tags> I tried this: ...
2
votes
2answers
68 views

new pattern required from an input file using sed or awk

I have data as below: MGW: VMG110 836-16 836-18 836-19 336-20 836-23 MGW: VMG120 3802-1 3802-2 3802-3 3456-1 3456-4 Required output is: VMG110:836-16&-18&&-20&-23 ...
2
votes
2answers
9k views

How can I replace text after a specific word using sed?

I have a file named .ignore. In need to replace the projdir. For example: ignore \..* ignore README projdir Snake I need to replace Snake with, for example, "PacMan". I read the man page, but I ...
1
vote
3answers
332 views

Replace specified character between two strings?

i have something to accomplish. i need to replace all occurrence of & inside or between <ex> </ex> to #. actual example below: a & b & c <ex> a & b & c ...
1
vote
6answers
8k views

How can I use variables when doing a sed?

I want to do: cat update_via_sed.sh | sed 's/old_name/new_name/' > new_update_via_sed.sh in my program. But I want to use variables, e.g. old_run='old_name_952' new_run='old_name_953' I have ...
1
vote
4answers
836 views

Replace text between brackets

I'm using awk '{ gsub(/BAR|WIBBLE/, "FOO"); print }' to replace text in data like: SOMETHING [BAR, WIBBLE] SOMETHING [BAR] This gives the desired result of: SOMETHING [FOO, FOO] SOMETHING [FOO] ...
33
votes
4answers
3k views

Reverse grepping

Let's say, I have a really big text file (about 10.000.000 lines). I need to grep it from the end and save result to a file. What's the most efficient way to accomplish task?
6
votes
5answers
20k 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. ...
8
votes
4answers
5k views

Efficient in-place header removing for large files using sed?

The commands below may takes minutes depends on the file size. Is there any more effient method? sed -i 1d large_file
25
votes
9answers
7k views

Addition with 'sed'

I am trying to perform a mathematical operation with sed, but it continues to treat my variables as strings. The input is of this kind: $ echo 12 | sed 's/[0-9]*/&+3/' $ 12+3 I'd like to have ...
15
votes
6answers
24k views

SED: insert something to the last line?

The command inserts a tag to the beginning of a file: sed -i "1s/^/<?php /" file How can I insert something to the end of each file with SED?
4
votes
2answers
7k views

Sed: Replace N first occurrences of a character

I am looking to replace the 5 first occurences of the whitespace character per line inside a sed script. Here's what I have so far sed -e "s/ /;/" -e "s/ /;/" -e "s/ /;/" -e "s/ /;/" -e "s/ /;/" ...
14
votes
10answers
3k views

There must be a better way to replace single newlines only?

I am in the habit of writing one line per sentence because I typically compile things to LaTex, or am writing in some other format where line breaks get ignored. I use a blank line to indicate the ...
4
votes
4answers
16k views

How to parse JSON with shell scripting in Linux?

I have a JSON output from which I need to extract a few parameters in Linux. This is the JSON output: { "OwnerId": "121456789127", "ReservationId": "r-48465168", "Groups": ...
11
votes
3answers
5k views

Zero-fill numbers to 2 digits with sed

Input: 201103 1 /mnt/hdd/PUB/SOMETHING 201102 7 /mnt/hdd/PUB/SOMETH ING 201103 11 /mnt/hdd/PUB/SO METHING 201104 3 /mnt/hdd/PUB/SOMET HING 201106 1 /mnt/hdd/PUB/SOMETHI NG Desired output: 201103 ...
8
votes
2answers
13k 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 ...