Regular expressions are a means of matching a pattern of characters within a string.

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Lowercase all but the first (Uppercase) letter from UPPERCASE in cyrillic

To make all letters a lower case except the first letter. The first letter would look like "Uppercase" after I changed (from UPPERCASE in cyrillic). The rest (not UPPERCASED) leave unchanged. I'm ...
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Regular expression in bash script

This is my first time bash scripting so I'm probably making an easy mistake. Basically, I'm trying to write a script that gets the groups of a user, and if they are in a certain group, it will log ...
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419 views

Using a perl compatible regex with GNU grep -P

I'm using this regex (?<=\[')[^,]* on a file containing the following line disk = ['OVS/sdasd/asdasd/asdasd/something.img, w'] I want that to return OVS/sdasd/asdasd/asdasd/something.img How do I ...
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1answer
209 views

Brace expression does not work in find regex

I have two folders, CA01 and CA02 under current folder, foo: foo -+ | +-CA01 | +-CA02 When I type find . -regex ".*CA[0-9]+" -exec echo {} + Or find . -regex ...
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128 views

Why `rename` behaves differently whenever I use full path instead current path?

Ok, I'm answering a question where the OP have several repositories in Ubuntu that might be causing a problem installing unrelated software. I recommend disabling the PPA's using a single liner rename ...
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1answer
1k views

Get all regex matches between two patterns and print them to file

I've got a file with a bunch of long lines. I'd like to grab every group between two patterns and print them to a new file, one match per line. I could manage to do this with Python, but I'd prefer ...
2
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1answer
150 views

Regex to find NFS filesystems that aren't being mounted with nosuid, except for ones with special needs

I have a script that runs the command mount -v 2>/some/file, which I then parse with another script using the following regex: ^.*[\ \t]+type[\ \t]+nfs(?![\ \t]+.*\b(?:nosuid|nosetuid)\b).* The ...
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201 views

grep + operator

According to the grep manual: * The preceding item will be matched zero or more times. + The preceding item will be matched one or more times. Let's test it echo 'agb' | grep 'a.*b' # returns ...
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88 views

How can I reformat tabular data using AWK?

I have a file contain following output. ora.abc.db 1 ONLINE ONLINE serverA Open 2 ONLINE ONLINE serverB Open ora.xyz.db 1 ...
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2answers
228 views

VIM substitute occurrences of pattern after a particular word in a line

I have such lines in my text. text before pattern = garbage** text after pattern is pattern If in VIM I do %s/pattern/saturn/ it replaces all occurrences of pattern. But I only want to replace ...
2
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4answers
95 views

Alternative regex for {}

I am trying to replace all of this line, but the numbers: looktype="123" so only the numbers show up. Is this possible in any easy way? {sub ("look type=\"[0-9]{0,3}", "TEST")} I am trying this ...
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1answer
54 views

How to match a literal '*' with sed?

I have this line in my file called test.php 'dbs_password' => 'a8b*cyP0', and want to replace into: 'dbs_password' => 'password-here', So I use this sed command with syntax: $ sed -e ...
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65 views

Pattern repetition and regexp

Take the pattern [UGLER]* Can the string UUG match against it? I mean to say, is repetition allowed?
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2answers
132 views

regular expressions with grep

I have this command right here: grep -B10 -A10 '14:14:50 {"channels":["/alerts/6979/new"],"data":"New alerts for unit 6979"}' mygateway.log Rather than searching for 14:14:50 I would like the 50 to ...
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3answers
55 views

Stuck in separating chars into strings in my approach. Found a working approach but can not understand it

I am trying to figure out how to break a string to be on character per line. I.e ahebhaaa to be: a h e b h a a a I tried: $ echo ahebhaaa | sed 's/\(.\)\(.\)/\1\n\2/g' I.e. my ...
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2answers
241 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 ...
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4answers
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vim search numbers containing specific number of digits

I need to find specific length numbers in a big document. I tried to use regex for this. For example, If I need to search for numbers with exactly 2 digits, I use /d/d (i.e. /d twice followed by a ...
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638 views

sed : Ignore line starting whitespace for match

I want to replace the default listening port of httpd to 9090. I can edit the line in httpd.conf file using below sed -i "/^Listen/c\Listen 9090" /etc/httpd/conf/httpd.conf But the line Listen 80 ...
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854 views

grep for an alphanumeric strings of any length with a colon on each side

How would you grep for an alphanumeric strings of 1 to 50 characters (ideally, any length would work too) with a colon on each side – a typical result would be all the lines containing the string ...
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1answer
543 views

How to insert both vimscript variable and string into vim search and replace

I've only just found out about Vimscript's existence as of today, so forgive me if this question is more basic than it seems, but I've been struggling to find an answer to this question for the better ...
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1answer
190 views

Aptitude regex engine

I was trying to lookup the versions of libdb in the debian archives with something like that: $ aptitude search '~S~ndev$(~nlibdb~(\d~|-~)!~v~rnative)' which didn't work as expected so I changed ...
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4answers
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Match multiple regular expressions from a single file using awk

I'm trying to parse a HTML file using shell scripting. There are 4 different regular expressions that i need to catch: name= , age= , classs= , marks=. Using grep "name=\|age=\|class=\|marks=" ...
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251 views

How can I combine grep with file and extra regex

I have a file of strings in each line. For example: AAAAA BBBBB CCCCC etc I want to check each string one by one whether it exists in a series of files in a specific directory. I ...
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116 views

Regexp on data flow

I want to test if in my data flow, there is something, and do an exit code. I use gammu monitor, which provides a data flow, for example : [root@MYSERVER ~]# gammu monitor Press Ctrl+C to break... ...
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How to grep for pipe |

How can I grep for line containing pipe character | or for character >: files content: |this is test where is > this is none now what I need using grep command is grep -iE "<some ...
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418 views

Escaping * with Regular Expressions and Grep

I have a file that has unique lines that start with 2 stars (**). However when I run a grep command for grep \*\* fileName I get all of the lines in the file. This is very unusual, and what I ...
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4answers
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Can tr work with regex?

I have a file like this: AAAA BBBB CCCC DDDD etc Words in separate lines. I want to add them quotes using tr. So I tried the following: 1) To add a quote in the start of each word ...
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130 views

Remove 2 and 3 newlines in a text file but not 1

I'm developing on a max osx 10.8 and have no preferences to which tool to use probably sed but it doesn't matter. Update after comment: The input file uses windows new lines if that's complicates ...
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1answer
161 views

Why is this line included in the `logcheck` report email?

In addition to the Debian provided rulesets, I have added a file /etc/logcheck/ignore.d.workstation/wpasupplicant.local (owner root:logcheck, mode 0644) to my newly installed logcheck setup. I have ...
4
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1answer
370 views

grep: display filename once, then display context with line numbers

Our source code has error codes scattered throughout. Finding them is easy with grep, but I'd like a bash function find_code that I can execute (eg. find_code ####) which will provide output along ...
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1answer
180 views

vim regex to search for lines containing string1 AND string2

How in vim/vi can I search for all lines that contain string1 and string2, where either string can appear anywhere on the line separated by whitespace and possibly other words? I would also like to ...
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Pulling out keywords using standard command line utilities?

As an example, this is the pronunciation of "when" according to Wiktionary. enPR, IPA and X-SAMPA are different schemes for showing pronunciations. when:* {{a|US}} {{enPR|wĕn|hwĕn}}, ...
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1answer
184 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 ...
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312 views

Replace all occurences of \ except \N

I have a file like this: 1,2,subjects,\mat\hs,unix\,\Nato,\N,123,\N I want to replace all occurences of \ with #, except for \N, such that the output looks like this: ...
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mv files to a different path which is constructed via a regex replacement

I have a directory full of files stored in subdirectories according to their filename, i.e.: 20d1/d325/52d1/20d1d32552d1a95249e62662fbdf924dd72c4027.jpg ...
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117 views

Backreferencing with sed

I have a database containing a list of unsigned longs representing a bunch of memory addresses followed by an offset within two brackets (e.g. Mem[offset], 0x2322AD4[3]), and some other data. What I ...
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144 views

Tell a regex expression to skip the beginning of a line before matching

If I had a string like 45mb ./aaaa/bbbb/cccc/dddd and I use a regex like [^\/]*\/ it will match 45mb ./aaaa/bbbb/cccc/ I only want it to match ./aaaa/bbbb/cccc/ but I can't figure out how to do ...
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Forcing Bash to use Perl RegEx Engine

As you may already know, a lot of the features modern RegEx engines support (back referencing, lookaround assertions, etc.) are not supported by Bash RegEx engine. Following is a simple Bash script I ...
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1answer
84 views

What are the commands that you can use in the beginning of a sed command?

I initially learned to do sed search and replace like so: sed -e 's/<stuff>/<replacement>/' However I recently learned that these will do something different based on what command ...
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Change filename from lowercase to uppercase recursively

I have 1,000,000 files in some folders and subfolders. I want to rename them from lowercase to uppercase using shell commands. I don't want to modify the extension. only filename part. I have found ...
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4answers
389 views

using simple regex quantifier expression in grep

Does anyone know why ls | xargs -n 1 basename | grep -E '[0-9]{1}' does not only show occurrences of a single digit between 0-9? For example if I have: touch 1 touch 22 touch 333 touch test_file ...
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How can I grep for this or that (2 things) in a file?

I have a file that has "then"'s and "there"'s. I can $ grep "then " x.x x and then some x and then some x and then some x and then some and I can $ grep "there " x.x If there is no blob none ...
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2answers
75 views

Grep and regex, Why does the following return only a specific portion?

Why in the following: echo this is a line. | grep -o -E "[a-z]+\." The result is line. and not this is a line.? There is no word boundary or any other restriction on the regex.
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1answer
137 views

How to negate a regex inside another regex

That is, given a POSIX regex X, what POSIX regex is the complementary of X? (in a more detailed way: how to get regex X' that matches all strings that are not matched by X, but doesn't match any ...
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Removing second colon

Trying to create a simple script that lists mass mailing by the queue number that appears in /var/log/maillog. I'm starting off with this: [root@ditirdlns01 ~]# lsMails(){ grep -i ...
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extract part of string using sed

ls lib/oracle-11.2.0.3.0.txt | sed 's/lib.\([oracle.*]\)\.txt/\1/' It is giving the whole string instead of just oracle part until .txt What am I doing wrong? I can do it using awk as follows, but, ...
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127 views

Use grep with or [duplicate]

How do I search in a textfile with grep for the occurrence of a word or another word? I want to filter the apache log file for all lines including "bot" or "spider" cat ...
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4answers
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Extract substring using regular expression on a Unix file

I have file with below contents . /ABC/RTE/AD_900_VOP_123/OPP /ABC/RTE/TRE/AD_900_VOP_145/BBB /ABC/RTE/AN_900_VFP_124/FBF /ABC/RTE/HD_900_FOP_153/WEW /ABD/RDV/AD_900_VOP_123/OPP ...
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2answers
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syntax of ls --hide= and ls --ignore=

ls --hide and ls --ignore provides the possibility leave out files defined through regular expressions set after the --ignore= part. The latter makes sure that this option isn't turned off via -a, -A. ...
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Grep and sort several unsorted things in several lines (in one document)

I have a file with several unsorted things in one line which I want to put into a new file This is an example of part of the file I have: X1314448: SaMi|SM_g2554.t1 SaMi|SM_g5072.t1 Des|Des_g3808.t1 ...