Tagged Questions
0
votes
0answers
26 views
Grep word in one file, and use that word to match in FASTA file, adding the FASTA sequence to the first file [closed]
I want to grep several words in file1, and use each word to grep what follows after its match in file2.fasta. And then I want to add the thing that followed the match to the word I used into file03, ...
1
vote
2answers
42 views
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 ...
5
votes
1answer
68 views
What is the meaning of this test expression []? [duplicate]
I've seen someone use command:
ps -ef | grep [h]ttpd
and Output is:
apache 25125 31006 0 21:54 ? 00:00:00 /usr/sbin/httpd
apache 26869 31006 0 22:04 ? 00:00:00 ...
2
votes
2answers
55 views
How to find files with a certain subpath?
I need to find all xml-files that are placed in folders named config. Also config must be somewhere under a folder named trunk. For example, I am interested in all files like below:
...
0
votes
1answer
70 views
How to ask for specific parameters with grep?
I need to look in /usr/share/dict/words for a 5-letter word that starts with d or D, followed by a lowercase vowel, and ends with s. I have tried everything but to no avail.
1
vote
2answers
73 views
linux + match IP ADDRESS with 3 octets or with 4 octets
how to match IP address with 4 octets or with 3 octets in one command?
target - match xxx.xxx.xxx or xxx.xxx.xxx.xxx ( syntax should fit for Linux and Solaris )
how to merge the following commands ...
5
votes
3answers
212 views
difference between .* and * in regular Expression
I've a file named "test" that contains
linux
Unixlinux
Linuxunix
it's linux
l...x
now when i use grep '\<l.*x\>' , it matches :
linux
it's linux
l...x
but when i use grep '\<l*x\>' ...
1
vote
3answers
127 views
Trying to remove all ids from an HTML file with grep
I'm trying to remove all id=" "s from an .html file but I'm not sure where I am going wrong. I tried using regular expressions but all I am getting is the .html file rendering in my Ubuntu terminal.
...
0
votes
1answer
38 views
(e)grep and atomic grouping [comprehension question]
I am trying to understand the correct use of »atomic grouping« a.k.a. »independent subexpressions« a.k.a. »non-backtracking subpattern« [this are the terms I found ...
4
votes
2answers
154 views
greedy and lazy regular expressions (comprehension question)
I am teaching myself regular expressions, and I got stuck at »greedy« vs. »lazy« repeatings.
What I found out so far is that
»greedy« means that the RegExp ...
1
vote
1answer
93 views
Confused about word boundary
I have been researching this a lot, but I am still not clear on it. What does word boundary mean? What does it do?
So, for example, could someone explain this command to me please?
egrep ...
0
votes
3answers
159 views
Regular Expression for finding double characters in Bash
I am looking for a regular expression that finds all occurences of double characters in a text, a listing, etc. on the command line (Bash).
Main Question: Is there a simple way to look for sequences ...
1
vote
2answers
170 views
Regular expression problem(s) in Bash: [^negate] doesn't seem to work
When I execute ls /directory | grep '[^term]' in Bash I get a regular listing, as if the grep command is ignored somehow. I tried the same thing with egrep, I tried to use it with double and single ...
0
votes
3answers
64 views
regex suggestion
echo "223255/12345678 " | grep '[0-9a-zA-Z/\-\?:\(\)\.,"\+]{1,34}'
According to the regex, it can have any of 0-9 a-z A-Z / - ? : ( ) . , " + of upto 34 chars in any order. Am I ...
2
votes
3answers
182 views
awk, sed, grep, perl… which to print out in this case?
I have this syntax in a file (http response times from analog):
<thead><tr><th class="x">seconds</th><th class="R">reqs</th><th ...
-1
votes
3answers
449 views
How to tell grep to match special character at beginning of each word [duplicate]
I have certain questions regarding grep.
Why does the following command match '<Hello'?
$ grep -E "\<H" test
Hello World
<Hello
H<ello
What needs to be done to match '<Hello' only?
...
1
vote
2answers
107 views
grep: invalid content of \{\}
Here's the command :
grep '\(2\)[[:digit:]]\{\1\}' numbers
What I want is to match exactly 2 digits after the digit '2', 3 digits if I change the digit '2' to '3' in my expression, 4 digits if ...
...
-1
votes
1answer
49 views
Doing regex in python [closed]
I had a directory "/pcap_test" which contains several log files. Each file has a pattern like:
Pkt: 1 (358 bytes), LIFE: 1, App: itunes (INTO), State: TERMINATED, Stack: /ETH/IP/UDP/itunes, Error: ...
-1
votes
2answers
289 views
Meaning of asterisk (*) in grep
[USERNAME@host ~] echo -e 'prdxxx\ndadxxx' | grep "da*xxx"
prdxxx
dadxxx
[USERNAME@host ~] echo $SHELL
/bin/bash
[USERNAME@host ~] dpkg -l | grep -iw bash
ii bash ...
3
votes
4answers
678 views
grep lines starting with “1” in Ubuntu
I try to search for lines that start with "1" using
ls -1 | grep ^1*
but it returns lines that do not start with 1. What I am missing here?
2
votes
2answers
324 views
extract last match from logfile till end
Using sed, grep, awk, or ruby, what's a simple way to find the last match of a string in a larger log file, and send every line following it (inclusive) to another file?
Example:
grep -A222 ...
2
votes
1answer
115 views
grep all words with specified length, without letter x
So I am stuck here:
grep -E '^....c...c...$' shows all words with the expr I need. Now from this words I only need the ones that don't have a x.
Who can help me?
9
votes
2answers
659 views
How to run grep with multiple AND patterns?
I would like to get the multi pattern match with implicit AND between patterns, i.e. equivalent to running several greps in a sequence:
grep pattern1 | grep pattern2 | ...
So how to convert it to ...
1
vote
1answer
234 views
Using grep command and backreferencing
This is a pretty basic question, but I can't get my head around it. I'm learning Linux and one of the questions i've been given is;
*The word sentimentalment includes the same three characters ...
2
votes
2answers
313 views
Parse apache logs to exclude IP ranges
I need to look for some requests in a huge pile of apache logs. My only requirement is this:
I need to only view the requests coming from any IP address that is NOT included in a list of 50 IP ranges ...
1
vote
2answers
123 views
Match a simple Regex
I need to match this: (tt\d{1,10}) in a file with the file ending txt.
I have tried grep and ack-grep but without results.
ack-grep -G \.txt$ -g "(tt\d{1,10})"
11
votes
6answers
359 views
How can I grep a directory based on the contents of two successive lines?
How can I grep a directory for lines that contain "Foo", but only get matches when the next line also contains "Bar"?
11
votes
3answers
892 views
Online grep exercises?
Are there any online grep tutorials that would feature some online tool for performing exercises? For example, having some predefined text sample and being told what patterns to find and so forth? It ...
2
votes
2answers
529 views
How to do a regex search in a UTF-16LE file while in a UTF-8 locale?
EDIT: Due to a comment Warren Young made, it made me realize that I was not clear on one quite relevant point. My search string is already in UTF-16LE order (not in Unicode Codepoint order, which is ...
1
vote
2answers
312 views
Weird zsh grep -P behaviour
I connect to server with PuTTY from Windows.
I have a long yet not touched (I suppose) by hands of local admin config:
$ cat /opt/jira/.subversion/config
...
### must be enabled, which is ...
1
vote
2answers
172 views
How do I generate a list of the characters occurring before a certain character only in lines that contain another certain character using regex?
I know that's super confusing (total noob-sorry!). To clarify, I have a text file that looks like this:
407-OL?
408-2-OL?
408-OL?
418-het?
420-1 and 2- OL?
429-2-left unscored?
430-2-left both ...
8
votes
4answers
14k views
How do I grep for multiple patterns?
I want to find all lines in several files that match one of two patterns. I tried to find the patterns I'm looking for by typing
grep (foo|bar) *.txt
but the shell interprets the | as a pipe and ...
1
vote
1answer
160 views
What does this egrep command do?
What does this egrep command do?
egrep '[^A-M][0-9]+' /etc/passwd
So far I think it searches for any file in /etc/passwd that starts with A-M and includes the number(s) 0-9. Is that right?
3
votes
3answers
433 views
Extracting text from a text file in bash
I have a large text file that is all one line. In the text are several sections that looks like foo=12345 and I need to extract them all as separate lines, ignoring the rest of the file.
For ...
4
votes
1answer
2k views
grep for words of no more than a certain length
I'm looking for a way to grep things like: i log for E M, i 1 f x i 0, I xi 1, 3 1,. simply based on number of characters.
Nothing in that hypothetical output is longer than three characters. This ...
2
votes
2answers
1k views
What is the python equivalent of grep -v?
I like grep -v. I use it all the time. But I am also doing some text processing in python, and there is one crucial thing that I lack.
Usually, I use grep -v to take extraneous stuff out of text.
...
2
votes
1answer
516 views
Escaping of meta characters in basic/extended posix regex strings in grep
Is it possible to escape all meta characters of a string inside a variable before passing it to grep? I know similar question has been asked before on SE
(here) and also a good explanation here, but I ...
1
vote
2answers
2k views
Find all lines in a file with a certain character at a certain position
I have a lab question asking me to use grep with a regex pattern to match every word where the third letter from the beginning of the line is an "a" and save it with a redirect. How can I do that?
2
votes
1answer
2k views
grep and escaping a dollar sign
I want to know which files have the string $Id$.
grep \$Id\$ my_dir/mylist_of_files
returns 0 occurrences.
I discovered that I have to use
grep \$Id$ my_dir/mylist_of_files
Then I see that the ...
0
votes
1answer
248 views
Egrep: contains and does not contain
egrep -i '12-12.*\swarning' log.file | cless
The above will produce two lines with the date 12-12, followed by random characters, a white space, then Warning and more text.
2011-12-12 textetc ...
1
vote
3answers
202 views
grep equivalent of the kwrite regex [A-Z][A-Z]+
So, it took me ages, but I finally learned to think in terms of regular expressions, thanks to using them in kwrite.
But I still don't know how to translate that knowledge to grep. I love my grep, ...
4
votes
3answers
2k views
grep: Trailing backslash
I want to do a grep for \resources\. How do I do this?
I've tried:
grep \resources\
grep \\resources\\
grep "\resources\"
grep "\\resources\\"
None of these work.
1
vote
1answer
526 views
Difficulty making a regular expression to find at least 2 occurrences of a character in a file
I have a file containing random codes. Each code has ten characters in it, and I am trying to grep codes in the file that have at least 2 occurrences of a character. I am doing this:
grep DD* ...
0
votes
2answers
2k views
Using grep to match only a match group in a regular expression?
I need to set my keyboard layout with setxkbmap before launching Wine games, as I use Dvorak for typing and this breaks every game's controls. What I'd like to do is simply write a script that grabs ...
1
vote
2answers
506 views
How to treat a file as a single line with grep to apply a regexp search pattern?
I want to match everything that is between some lines with regexp but not this that match the start and the end. This sound to me as positive lookbehind and positive lookahead
start text
bla ...
2
votes
3answers
591 views
How to cut the output to only gather the filename and get-parameter?
I have multiple files with multiple links that are formatted like this:
<a href="http://example.com/fnord.layername.html?parameter=FOO-_-BAR-_-FNORD" class="poit">
<img ... />
...
4
votes
1answer
534 views
How can I match the page break character in a regular expression?
Nano calls it ^L, but of course, typing something like
$ grep -v "^\^L" file
doesn't work. Its unicode codepoint is 000C. How can I match it in a regular expression?
1
vote
2answers
287 views
pattern search and display the last occuring pattern?
I have a log file containing startup and shutdown times for everday.
I want to see the last pattern pattern for startup and shutdown(which is located at the end of the file being updated everyday).
...
4
votes
2answers
309 views
grep caret appears to have no effect
I was under the impression that a caret symbol means "beginning of the line" with Extended POSIX regular expressions.
However, when I use it with grep it behaves unexpectedly.
#grep --version
GNU ...
0
votes
1answer
205 views
What does ^> mean in a grep pattern?
What does this command do?
grep "<[^>]*>" inuux.xml
What is searching for?
