Questions tagged [regular-expression]
Regular expressions are a means of matching a pattern of characters within a string.
0
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0answers
6 views
Grep not understanding whitespace delimiter?
In the following example,
root@Cassiopeia:~# apt-file search apache2.conf | grep -E "apache2.conf\b"
apache2: /etc/apache2/apache2.conf
apache2-doc: /usr/share/doc/apache2-doc/examples/apache2/...
-3
votes
2answers
44 views
Unix shell : substring with regular expression [on hold]
I have this text:
1234
I want to use a regex to select all except the first digit (in this case 1) -
so a pattern that selects
234
How can I do this?
I can't use variables, only regex. And also I ...
0
votes
0answers
32 views
sed command to insert between two strings that are returned from another sed command
I have a YAML file that's about 25K lines and I have about 450 instances where I need to insert between two specific lines.
Here's an example of the file entries:
- changeSet:
id: ...
1
vote
2answers
30 views
Regular expressions in grep
The man page for grep reads (emphasis mine)
REGULAR EXPRESSIONS
A regular expression is a pattern that describes a set of strings. Regular expressions are
constructed analogously to ...
0
votes
0answers
47 views
Complex string replace - multiple files, multiple different strings, must include certain text
I have a number of XML files (Atlassian Confluence space exports FYI), that I need to parse through to replace certain strings, as long as the line begins with a set string.
Here is an example of a ...
0
votes
4answers
54 views
How to extract the CSV file name from each line of this file
I have a file which contains lines like those:
-rw-rw-rw 1 root root 6379 May 24 2016 test1.CSV
-rw-rw-rw 1 root root 23249 May 25 2016 test2.CSV
-rw-rw-rw 1 root root 2995 May 26 2016 test3.CSV
...
-1
votes
1answer
30 views
\back slash charectar and . in grep
I am confused about the backslash character \ and single quotations inside grep. From my understanding it preserves the literal meaning. For example
if I do echo 'This is \., it gives me This is \.
...
2
votes
1answer
172 views
Regex in IF condition in awk
I have awk script file as below. I need to add another condition in the if statement to check if the string contains atleast one alphabet. How can I add the extra condition to the present if statement?...
0
votes
2answers
34 views
grep STOP regex replacing -A option
I'm looking/searching for a way to make grep stop when finding the "|_" specific string after having found
the search string.
for example, i want to print ONLY the lines starting 2 lines above "...
3
votes
2answers
693 views
Merge two greps into single one
I need to extract an ID from the output of another command. Currently my extracting command looks like:
someID=$(command | grep -oP '(?:^Successfully\sbuilt\s)([\da-z]{12}$)' | grep -oP '([a-z\d]{12})...
3
votes
2answers
56 views
Using regular expressions in “less”
I'm trying to use a regular expression in the man page of Bash by using less.
I press / in less to enter a pattern, and I type z and press the Enter. I expected it to not match upper-case z (Z), but ...
3
votes
0answers
44 views
Renaming files with vidir (moreutils)
I'm trying to use vidir from the moreutils package and I have the following issue:
When I load the files I want to rename with vidir like this:
$ vidir
or like this:
$ find -type f | vidir --...
0
votes
2answers
39 views
Need regex to replace the whole line, but the last optional character
It sounds like it should be trivial task, but I cannot figure it out, so I decided to ask. I need to replace the whole line, but optional last character. For instance, I want:
abcd to become efgh but
...
0
votes
0answers
24 views
Rename multiple files, removing text before prefix [duplicate]
I have 70 ish csv files that look something like:
C03-10dfg-PI-35.csv
C03-fgfg-PI-36.cvs
C03-dfdf-PI-37.csv
....
....
....
I want to rename all files to remove everything before PI.
Outputs:
PI-35....
0
votes
3answers
50 views
In a bash shell script, how to rename multiple files, keeping only the numbers and the extension of the original file names?
I have a directory with a bunch of files with names like this:
generic name- dd -01 _.txt
generic name- dd -02 _.txt
generic name- dd -03 _.txt
generic name- dd -04 _.txt
And I want to rename all of ...
4
votes
2answers
94 views
When and why did ^ and $ take on their meanings of “beginning of line” and “end of line?”
Many command-line tools (grep, flex, etc.) use the ^ symbol to denote "beginning of line" and the $ symbol to denote "end of line." When did this convention arise? It seems perfectly reasonable to ...
-2
votes
1answer
53 views
How to match string in file
I'm trying to reproduce this code in Python to Bash
import re
w = open("filetest.txt")
for item in re.findall(r'STRING:\s*(.+)"', w.read()):
print item
In Bash, but I do not know if it's correct, ...
-2
votes
1answer
41 views
grep to find lines that contain six or more non-vowel characters in a row
Using grep and regular expressions, I need to output all lines in a file that contain at least six characters in a row that aren't vowels. This includes any consonants, punctuation, numbers, etc.
0
votes
3answers
63 views
How to test if a folder exists using regular expression in Bash?
as all know we can check easily if folder exists by the following bash command
[[ -d /opt/presto-server ]] && echo folder exist
but when we have folder as
/opt/presto-server-32.34
then how ...
2
votes
1answer
35 views
Recursively find directories but do not print subdirectories of matches
Considering the following directory structure:
dir1
[domain.com] foo dir1
subdir1
subdir2
FooFile
dir2
[domain.com] foo dir2
subdir3
[domain.com] foo dir3
subdir4
...
1
vote
2answers
51 views
append brackets to all constants beginning with L:: where it not exist on end
I have many PHP Files where I need to add on end "()" to every constant beginning with "L::" which don't have on end "(". It should by applied to all *.php including subfolders) :
L::WHAT_EVER
<?=...
0
votes
2answers
78 views
how to deal with sed if Argument list too long
Trying to apply the following command:
sudo sed -i "s/auth-user-pass/auth-user-pass pass.txt/g" *.ovpn
But i keep getting the following error:
sudo: unable to execute /bin/sed: Argument list too ...
-2
votes
1answer
41 views
Is there any initiative to transition all shell globs into standard regex?
I see many imagination between shell globs (wildcards) syntax and standard regex.
Is there (or was there) any initiative to transition all shell globs into standard regex?
By that I mean, using ...
0
votes
4answers
51 views
how to let part of the regex (that is variable) be matched literally, ignoring control characters?
I got some filenames containing characters that are regex special control ones.
I need to prepare a regex that considers all these characters literally.
Simplified test case:
strFilenameOnDB="...
-1
votes
3answers
70 views
What does the following number-processing sed code mean?
I came across a code in script which add ',' after every 3 digits from backwards. the code only considers numeric data.
Following is the code.
sed 's/\(^\|[^0-9.]\)\([0-9]\+\)\([0-9]\{3\}\)/\1\2,\3/...
-1
votes
1answer
53 views
How to grep for a particular string?
I am trying to get a string that matches the following pattern: starts with foo and finishes with bar.
grep -e "^foo*bar$"
4
votes
3answers
291 views
Extract substring according to regexp with sed or grep
In a (BSD) UNIX environment, I would like to capture a specific substring using a regular expression.
Assume that the dmesg command output would include the following line:
pass2: <Marvell ...
1
vote
0answers
58 views
sed command is replacing the replaced text?
I am writing a bash script to rename icons. Specifically I am trying to change "icon-close-m" to "icon-close icon-size-medium" in HTML files. (though it could contain any substring besides "close", as ...
1
vote
1answer
37 views
Why is this regex not working in awk?
I have a text file as such:
Attribute 1.............. : attribute value
Encode Date............................. : JUL 2007
Attribute 22076.......... : attribute value`
I want to extract the JUL ...
0
votes
1answer
42 views
Multiple replacements using regular expressions in python
Can I use regex in python to have multiple types of substitutions? Like in this string "hello, this is me" I want to replace 'hello' with 'hi' and 'this' with 'its'.
Can I do it in a single line? Or ...
0
votes
1answer
25 views
How to specify regex quantifiers with mawk?
I'm familiar with the concept of specified bounded regex quantifiers as follows:
Quantifier Legend Example Sample Match
{3} Exactly three times \D{3} ABC
{2,4} ...
0
votes
2answers
47 views
Grep in bash issues
Sample string:
--000000000000f104a6057d4a0a10
Here I need to get for sure: "--"
Same files also contain a lot of similar strings; ------=_, --=_ , -----------, --< which currently also get ...
0
votes
2answers
27 views
split file lines by regex delimeter
I want to split each line from input file by a non-alphanumeric regex \W and print all the split chunks in the output file like so:
Input file:
www.wifi.in.ua
YI-HondBrychka
Output file:
www
wifi
...
0
votes
2answers
53 views
Can't replace my regex matches
I can filter files, I can can stream the matches of my regex ...
However, I need to remove exactly that, from a large file.
Regex:^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$
sed ...
0
votes
1answer
101 views
Regex expression for IP address/CIDR in bash
I want to check if the user input is a valid IP address/CIDR in bash and I am using regular expressions to do that. So valid CIDR should be 0-32 and for IP from (1-254).(1-255).(1-255).(1-255)/(1-32) ...
1
vote
2answers
104 views
How to mass rename files with regular expressions [closed]
I have a bunch of folders in a directory with files in them. Most of the filenames have region codes (retropie), and the scrubber will not match roms with single letter region codes (u,j,e,etc.). I ...
0
votes
4answers
90 views
grep IPs and port number into one line
Using grep and cut I have returned the IP and ports of the nmap scan result which looks like this:
192.168.1.221
80
443
192.168.1.223
25
Desired output:
192.168.1.221:80
192.168.1.221:443
192.168....
1
vote
2answers
73 views
grep for single back slash
I am trying to grep for the mount output to see the options for the root directory.
Why the following pattern (whitespace before and after a slash) is not working (with and without extended grep)
/...
2
votes
4answers
90 views
Removing (possibly nested) text quotes in command line
I need to parse large amounts text in command line and replace all (possibly nested) text quotes with spaces. Quotes are marked with specific syntax: [quote=username]quoted text[/quote].
Example ...
0
votes
0answers
30 views
Commenting out a specific host configuration in a Nagios configuration file
I have lots of Nagios configuration files like the one below in a directory, and I need to remove a host from monitoring.
define host{
host_name nmo
use aix-server
alias
hostgroups +...
1
vote
5answers
50 views
remove all lines with nullbytes/corrupt data
So I recovered a text file from an old hdd, but I failed to completely recover all of the data. The data that wasn't correctly recovered has returned as null bytes. How can I remove every line from ...
2
votes
2answers
46 views
how to find the real path of folder with regular expression
presto is distributed SQL query engine ,
and when we installed the presto then it should be created the following home folder
/application/DB/presto/presto-server-0.216
so we can say that
in ...
0
votes
1answer
68 views
Bash regex and IFS split
I have the following problem: I want to extract text that is inside brackets from a string (with or without the brackets). My string looks like this:
STR="[1] [2][345] [678 9] foo bar"
I initially ...
0
votes
0answers
45 views
Remove all words from a file except certain words
I have a file which represent a list of SQLs where caluses.
I want to remove everything that is not the columns names, and, or and where(case insensitive). In addition if it can also remove new lines ...
0
votes
1answer
74 views
sed: escaped square closing bracket does not match
Goal: replace  with <img src="url.png" alt="alttext">.
The ! and (...) parts work fine, it's the [...] part that I can't get to work.
As a simple example, I want to match ...
0
votes
2answers
97 views
Use FIND with MV to rename files. Delete the found string then prepending it to the filename?
find . -type f -name '*authors-name-string*' -exec bash -c 'mv "$0" "${0/authors-name-string/}"' {} \;
I am trying to rename files nested in several layers of directories that contain an author's ...
-1
votes
2answers
41 views
* in awk (metacharacters)
Can you explain me how * works?
I have an input:
U 8649 275 Asia
Canada 3852 25 North America
China 3705 1032 Asia
USA 3615 237 North America
India 1267 746 -Asia
...
4
votes
1answer
381 views
Awk - metacharacters
What is the difference between [+-] and [-+]. It seems to me doing the same thing. And what does [A-Za-z-]+ do?
Or I tried
awk '/[^-]/' contries
and I expected nothing as an output.
7
votes
4answers
416 views
Why does regex `“\.pdf”` match `/…/pdf…/…` in gawk, but not in mawk?
From How can I extract only the pid column and only the pathname column in the lsof output?
awk '{ for (i=9; i<=NF; i++) {
if ($i ~ "string" && $1 != "wineserv" && $5 == "REG" &...
1
vote
0answers
82 views
How to improve this 'sed' search & replace command?
How to search and replace recursively through multiple files in a directory, using essential tools installed in mostly any Debian/Ubuntu machine?
There are multiple answers in Stack* where to find ...
