how can I extract a pattern only using grep - linux

How can we extract the contents present inside KeyProviderType tag only using grep command from the folllowing pattern?
<ContentProtectKeyProfiles-row><Name>PREM7</Name><Domain>42.0.112.121</Domain<ProfileType>4</ProfileType>
<Protocol>HTTP</Protocol><Port>80</Port><KeyProviderType>HLS-AES-128</KeyProviderType</ContentProtectKeyProfiles-row>

a#x:/tmp$ cat s.xml
<ContentProtectKeyProfiles-row> <Name>PREM7</Name> <Domain>42.0.112.121</Domain> <ProfileType>4</ProfileType> <Protocol>HTTP</Protocol> <Port>80</Port> <KeyProviderType>HLS-AES-128</KeyProviderType> </ContentProtectKeyProfiles-row>dhruv#dhruv-pathak:/tmp$
a#x:/tmp$ cat s.xml | grep -oe "<KeyProviderType>.*</KeyProviderType>"
<KeyProviderType>HLS-AES-128</KeyProviderType>

Don't use grep to process XML files. Use a proper XML parser. For example, using xsh, I can just run
open in.xml ;
echo (//KeyProviderType) ;
BTW, I had to fix 2 tags that were missing > in your input.

You can try to use gnu awk (due to RS)
awk -v RS="KeyProviderType" 'NR%2==0 {gsub(/>|<\//,"");print}' file
HLS-AES-128

You may use regex lookahead's and lookbehind's, provided your grep support -P flag.
cat s.xml | grep -oP "(?<=<KeyProviderType>).*(?=</KeyProviderType>)"

Related

How to grep while excluding some words?

I wanted to grep the word "force" but most of the output listed is from the command -force.
When I did grep -v "-force" filename , it says grep : orce most probably because of the -f command.
I just want to find a force signal from files using grep. How?
use grep -v -- "-force" - the double - signals that there are no more options being expected.
If you want to grep specific word from file then we can use cat command
# cat filename.txt | grep force
For other basic Commands
this line maybe simpler:
grep '[^-]force' tmp
it says: grep "force", but only if it does not has a prefix - by using [^]. See some simple regular expression examples here.
Use [-] to remove the special significance. Check this out:
> cat rand_file.txt
1. list items of random text
2. -force
3. look similar as the first batch
4. force
5. some random text
> grep -v "-force" rand_file.txt
grep: orce: No such file or directory
> grep -v "[-]force" rand_file.txt | grep force
4. force
>

How to replace Pipe with a new line in Linux?

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

grep a particular content before a period

I am trying to read/grep a particular word or content that is before a period (.).
e.g. file1 has abinaya.ashok and I want to grep whatever is before the period (.) without hardcoding anything.
if I try
grep \.\ file1
it gives abinaya.ashok.
I've tried: grep\*\.\ file1
it doesn't give anything.Can we find it using grep commands or should we do it only using awk command? Any thoughts?
Using GNU grep for PCRE regex (for non-greedy and positive look-ahead), you can do:
echo 'abinaya.ashok' | grep -oP '.*?(?=\.)'
abinaya
Using awk:
echo 'abinaya.ashok' | awk -F\. '{print $1}'
abinaya
Check the following simple examples.
Including the dot:
$ echo abinaya.ashok | grep -o '.*[.]'
abinaya.
Without the dot:
$ echo abinaya.ashok | grep -o '^[^.]\+'
abinaya
Hope I understand you correctly:
sed -n 's/\..*//p' file1 | grep whatever
sed expression will print only part before dot (lines without dot are not printed).
Now use grep to search what you need.

How to extract distinct part of a string from a file in linux

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

Pipe output to use as the search specification for grep on Linux

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.

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