Please, accept my apologies, if this question was asked before. I am new and do not know how to do it. I have a file containing the data like this:
name=1|surname=2|phone=3|email=4
phone=5|surname=6|name=7|email=8
surname=9|phone=10|email=11|name=12
phone=13|email=14|name=15|surname=6
I would like to have a file like this:
name=1
name=7
name=12
name=15
Thanks in advance!
Say names.txt is your file, then use something like :
cat names.txt | tr "|" "\n" | grep "^name="
tr transforms | to newlines
grep filters for the lines with name
And here is a one command solution with GNU awk:
awk -v RS="[|\n]" '/^name=/' names.txt
the -v RS="[|\n]' set the record separatro to|` or newline
the /^name=/ filters for records starting with name= (and implicitly prints them)
I would go for the solution of #Lars, but I wanted to test this with "lookbehind".
With grep you can get the matches only with grep -o, but the following line will also find surname:
grep -o "name=[0-9]*" names.txt
You can fix this a little by looking for the character before name (start of line with ^ or |).
grep -o "(^|\|)name=[0-9]*" names.txt
What a fix! Now you get the right names, but sometimes with an extra |.
With \K (and grep option -P) you can tell grep to use something for the matching but skip it during output.
grep -oP "(^|\|)\Kname=[0-9]*" names.txt
Related
Sorry title is not very clear.
So let's say I'm grepping recursively for urls like this:
grep -ERo '(http|https)://[^/"]+' /folder
and in folder there are several files containing the same url. My goal is to output only once this url. I tried to pipe the grep to | uniq or sort -u but that doesn't help
example result:
/www/tmpl/button.tpl.php:http://www.w3.org
/www/tmpl/header.tpl.php:http://www.w3.org
/www/tmpl/main.tpl.php:http://www.w3.org
/www/tmpl/master.tpl.php:http://www.w3.org
/www/tmpl/progress.tpl.php:http://www.w3.org
If you only want the address and never the file where it was found in, there is a grep option -h to suppress file output; the list can then be piped to sort -u to make sure every address appears only once:
$ grep -hERo 'https?://[^/"]+' folder/ | sort -u
http://www.w3.org
If you don't want the https?:// part, you can use Perl regular expressions (-P instead of -E) with variable length look-behind (\K):
$ grep -hPRo 'https?://\K[^/"]+' folder/ | sort -u
www.w3.org
If the structure of the output is always:
/some/path/to/file.php:http://www.someurl.org
you can use the command cut :
cut -d ':' -f 2- should work. Basically, it cuts each line into fields separated by a delimiter (here ":") and you select the 2nd and following fields (-f 2-)
After that, you can use uniq to filter.
Pipe to Awk:
grep -ERo 'https?://[^/"]+' /folder |
awk -F: '!a[substr($0,length($1))]++'
The basic Awk idiom !a[key]++ is true the first time we see key, and forever false after that. Extracting the URL (or a reasonable approximation) into the key requires a bit of additional trickery.
This prints the whole input line if the key is one we have not seen before, i.e. it will print the file name and the URL for the first occurrence of each URL from the grep output.
Doing the whole thing in Awk should not be too hard, either.
In a very large file I need to find the position (line number) of a string, then extract the 2 lines above and below that string.
To do this right now - I launch vi, find the string, note it's line number, exit vi, then use sed to extract the lines surrounding that string.
Is there a way to streamline this process... ideally without having to run vi at all.
Maybe using grep like this:
grep -n -2 your_searched_for_string your_large_text_file
Will give you almost what you expect
-n : tells grep to print the line number
-2 : print 2 additional lines (and the wanted string, of course)
You can do
grep -C 2 yourSearch yourFile
To send it in a file, do
grep -C 2 yourSearch yourFile > result.txt
Use grep -n string file to find the line number without opening the file.
you can use cat -n to display the line numbers and then use awk to get the line number after a grep in order to extract line number:
cat -n FILE | grep WORD | awk '{print $1;}'
although grep already does what you mention if you give -C 2 (above/below 2 lines):
grep -C 2 WORD FILE
You can do it with grep -A and -B options, like this:
grep -B 2 -A 2 "searchstring" | sed 3d
grep will find the line and show two lines of context before and after, later remove the third one with sed.
If you want to automate this, simple you can do a Shell Script. You may try the following:
#!/bin/bash
VAL="your_search_keyword"
NUM1=`grep -n "$VAL" file.txt | cut -f1 -d ':'`
echo $NUM1 #show the line number of the matched keyword
MYNUMUP=$["NUM1"-1] #get above keyword
MYNUMDOWN=$["NUM1"+1] #get below keyword
sed -n "$MYNUMUP"p file.txt #display above keyword
sed -n "$MYNUMDOWN"p file.txt #display below keyword
The plus point of the script is you can change the keyword in VAL variable as you like and execute to get the needed output.
I'm using the following command to extract distinct urls that contain .com extension and may contain .us or whatever country extension.
grep '\.com' source.txt -m 700 | uniq | sed -e 's/www.//'
> dest.txt
The problem is that, it extracts urls in the same doamin, the thing tht I don't want. Ex:
abc.yahoo.com
efg.yahoo.com
I only need the yahoo.com. How can I using grep or any other command extract distinct domain names only ?
Maybe something like this?
egrep -io '[a-z0-9\-]+\.[a-z]{2,3}(\.[a-z]{2})?' source.txt
Have you tried using awk in instead of sed and specify "." as the delimiter and only print out the two last fields.
awk -F "." '{ print $(NF-1)"."$NF }'
Perhaps something like this should help:
egrep -o '[^.]*.com' file
I am in need of trimming some text with grep, I have tried various other methods and havn't had much luck, so for example:
C:\Users\Admin\Documents\report2011.docx: My Report 2011
C:\Users\Admin\Documents\newposter.docx: Dinner Party Poster 08
How would it be possible to trim the text file, so to trim the ":" and all characters after it.
E.g. so the output would be like:
C:\Users\Admin\Documents\report2011.docx
C:\Users\Admin\Documents\newposter.docx
use awk?
awk -F: '{print $1':'$2}' inputFile > outFile
you can use grep
(note that -o returns only the matching text)
grep -oe "^C:[^:]" inputFile > outFile
That is pretty simple to do with grep -o:
$ grep -o '^C:[^:]*' input
C:\Users\Admin\Documents\report2011.docx
C:\Users\Admin\Documents\newposter.docx
If you can have other drives just replace C by .:
$ grep -o '^.:[^:]*' input
If a line can start with something different than a drive name, you can consider both the occurrence a drive name in the beginning of the line and the case where there is no such drive name:
$ grep -o '^\(.:\|\)[^:]*' input
cat inputFile | cut -f1,2 -d":"
The -d specifies your delimiter, in this case ":". The -f1,2 means you want the first and second fields.
The first part doesn't necessarily have to be cat inputFile, it's just whatever it takes to get the text that you referred to. The key part being cut -f1,2 -d":"
Your text looks like output of grep. If what you're asking is how to print filenames matching a pattern, use GNU grep option --files-with-matches
You can use this as well for your example
grep -E -o "^C\S+"| tr -d ":"
egrep -o "^C\S+"| tr -d ":"
\S here is non-space character match
How do I pipe the output of grep as the search pattern for another grep?
As an example:
grep <Search_term> <file1> | xargs grep <file2>
I want the output of the first grep as the search term for the second grep. The above command is treating the output of the first grep as the file name for the second grep. I tried using the -e option for the second grep, but it does not work either.
You need to use xargs's -i switch:
grep ... | xargs -ifoo grep foo file_in_which_to_search
This takes the option after -i (foo in this case) and replaces every occurrence of it in the command with the output of the first grep.
This is the same as:
grep `grep ...` file_in_which_to_search
Try
grep ... | fgrep -f - file1 file2 ...
If using Bash then you can use backticks:
> grep -e "`grep ... ...`" files
the -e flag and the double quotes are there to ensure that any output from the initial grep that starts with a hyphen isn't then interpreted as an option to the second grep.
Note that the double quoting trick (which also ensures that the output from grep is treated as a single parameter) only works with Bash. It doesn't appear to work with (t)csh.
Note also that backticks are the standard way to get the output from one program into the parameter list of another. Not all programs have a convenient way to read parameters from stdin the way that (f)grep does.
I wanted to search for text in files (using grep) that had a certain pattern in their file names (found using find) in the current directory. I used the following command:
grep -i "pattern1" $(find . -name "pattern2")
Here pattern2 is the pattern in the file names and pattern1 is the pattern searched for
within files matching pattern2.
edit: Not strictly piping but still related and quite useful...
This is what I use to search for a file from a listing:
ls -la | grep 'file-in-which-to-search'
Okay breaking the rules as this isn't an answer, just a note that I can't get any of these solutions to work.
% fgrep -f test file
works fine.
% cat test | fgrep -f - file
fgrep: -: No such file or directory
fails.
% cat test | xargs -ifoo grep foo file
xargs: illegal option -- i
usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements]] [-J replstr]
[-L number] [-n number [-x]] [-P maxprocs] [-s size]
[utility [argument ...]]
fails. Note that a capital I is necessary. If i use that all is good.
% grep "`cat test`" file
kinda works in that it returns a line for the terms that match but it also returns a line grep: line 3 in test: No such file or directory for each file that doesn't find a match.
Am I missing something or is this just differences in my Darwin distribution or bash shell?
I tried this way , and it works great.
[opuser#vjmachine abc]$ cat a
not problem
all
problem
first
not to get
read problem
read not problem
[opuser#vjmachine abc]$ cat b
not problem xxy
problem abcd
read problem werwer
read not problem 98989
123 not problem 345
345 problem tyu
[opuser#vjmachine abc]$ grep -e "`grep problem a`" b --col
not problem xxy
problem abcd
read problem werwer
read not problem 98989
123 not problem 345
345 problem tyu
[opuser#vjmachine abc]$
You should grep in such a way, to extract filenames only, see the parameter -l (the lowercase L):
grep -l someSearch * | xargs grep otherSearch
Because on the simple grep, the output is much more info than file names only. For instance when you do
grep someSearch *
You will pipe to xargs info like this
filename1: blablabla someSearch blablabla something else
filename2: bla someSearch bla otherSearch
...
Piping any of above line makes nonsense to pass to xargs.
But when you do grep -l someSearch *, your output will look like this:
filename1
filename2
Such an output can be passed now to xargs
I have found the following command to work using $() with my first command inside the parenthesis to have the shell execute it first.
grep $(dig +short) file
I use this to look through files for an IP address when I am given a host name.