grep extract simple url - without scheme - regex

I need to extract n url from a file. I've started with:
grep -E -o 'ftp://\S*' $filename
I know, that this particular url will start with ftp scheme and will end with some white character (space or newline).
I receive something like:
ftp:/dir/some_file.ext
But I need just a path (/dir/some_file.ext). Without scheme (ftp:// part)
Can I do it with the first regexp? Do I have to use a second one?
I cannot use anything else then grep/egrep.

If your grep supports -P (PCRE flag) then you can use:
grep -oP 'ftp:/\K/\S*' $filename
/dir/some_file.ext
If fore some reason you don't have grep -P available then pipe with another grep:
grep -oE 'ftp://\S*' file | grep -oE '/[^/].*'
/dir/some_file.ext

This gnu awk (due to multiple characters in Record Selector) may also do:
awk -v RS="ftp:/" 'NR>1 {print $1}' file

Related

grep to match filename in full path

I want to "extract" the file name in a full path string using grep.
For example:
In /etc/network/interfaces I want to match "interfaces".
In /home/user/Documents/report.pdf I want to match "report.pdf".
Basically I want the opposite of:
$ ls /etc/network/interfaces | grep "^.*/"
I tried:
$ ls -p /etc/network/interfaces | grep "/.*$"
But it won't be the last slash (/), all chars (.*), until the end ($). Since slashes are chars as well, it matches all the path.
Does anyone know a way to match only the last part? Something like (from last slash until the end.
Thank you,
awk, getting the / separated last field:
% awk -F/ '{print $NF}' <<<'/etc/network/interfaces'
interfaces
% awk -F/ '{print $NF}' <<<'/home/user/Documents/report.pdf'
report.pdf
grep, getting the portion after last /:
% grep -o '[^/]\+$' <<<'/etc/network/interfaces'
interfaces
% grep -o '[^/]\+$' <<<'/home/user/Documents/report.pdf'
report.pdf
sed, replacing everything upto the last / with null:
% sed 's_.*/__' <<<'/etc/network/interfaces'
interfaces
% sed 's_.*/__' <<<'/home/user/Documents/report.pdf'
report.pdf
How about simply matching on not /? Also, for extraction, you need the -o flag to grep.
ls -p /etc/network/interfaces | grep -o '[^/]*$'
As said in the first comment you can directly try using awk something like:
ls -l /etc/networks | awk '{print $NF}' | awk -F "/" '{print $NF}'
It should be possible to trim these 2 awk pipes as well

Regex to match an IP adress within a colon and a slash with grep

The lines in the file I want to search look like this:
log:192.1.1.128/50098
log:192.1.1.11/22
...
Now I tried the following RegEx but none of them worked:
grep -oE "\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b" file
grep -oE "\b((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}\b"
grep -oE "\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b"
You can do this without regex using awk (on this simple example):
awk -F":|/" '{print $2}' file
192.1.1.128
192.1.1.11
To test if its IP contains three .:
awk -F":|/" '{n=split($2,a,".");if (n=4) print $2}' file
192.1.1.128
192.1.1.11
You could use grep also.
$ grep -oP '.*?:\K[^/]*(?=/)' file
192.1.1.128
192.1.1.11
Grep's extended regexp parameter -E won't support \d, you need to use [0-9] instead of \d.
$ grep -oE "\b[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\b" file
192.1.1.128
192.1.1.11

How can I extract the content between two brackets?

My input:
1:FAILED + *1 0 (8328832,AR,UNDECLARED)
This is what I expect:
8328832,AR,UNDECLARED
I am trying to find a general regular expression that allows to take any content between two brackets out.
My attempt is
grep -o '\[(.*?)\]' test.txt > output.txt
but it doesn't match anything.
Still using grep and regex
grep -oP '\(\K[^\)]+' file
\K means that use look around regex advanced feature. More precisely, it's a positive look-behind assertion, you can do it like this too :
grep -oP '(?<=\()[^\)]+' file
if you lack the -P option, you can do this with perl :
perl -lne '/\(\K[^\)]+/ and print $&' file
Another simpler approach using awk
awk -F'[()]' '{print $2}' file

What is the Unix command to display all lines of a file with two certain strings

Basically, I have a file that I want to search and display only the lines that have the strings 'abc' and 'vhg'. What is the Unix command for this?
You can use grep for it:
grep abc file.txt | grep vhg
OR
you can use awk:
awk '/abc/ && /vhg/' file.txt
One more way with grep:
grep .*abc.*vhg file.txt
Use the grep command.
grep 'word1\|word2\|word3' /path/to/file
Example:
grep 'abc\|vhg' filename
Since a sed solution has not yet been given:
sed -n '/abc/{ /vhg/p; }'

Match two strings in one line with grep

I am trying to use grep to match lines that contain two different strings. I have tried the following but this matches lines that contain either string1 or string2 which not what I want.
grep 'string1\|string2' filename
So how do I match with grep only the lines that contain both strings?
You can use
grep 'string1' filename | grep 'string2'
Or
grep 'string1.*string2\|string2.*string1' filename
I think this is what you were looking for:
grep -E "string1|string2" filename
I think that answers like this:
grep 'string1.*string2\|string2.*string1' filename
only match the case where both are present, not one or the other or both.
To search for files containing all the words in any order anywhere:
grep -ril \'action\' | xargs grep -il \'model\' | xargs grep -il \'view_type\'
The first grep kicks off a recursive search (r), ignoring case (i) and listing (printing out) the name of the files that are matching (l) for one term ('action' with the single quotes) occurring anywhere in the file.
The subsequent greps search for the other terms, retaining case insensitivity and listing out the matching files.
The final list of files that you will get will the ones that contain these terms, in any order anywhere in the file.
If you have a grep with a -P option for a limited perl regex, you can use
grep -P '(?=.*string1)(?=.*string2)'
which has the advantage of working with overlapping strings. It's somewhat more straightforward using perl as grep, because you can specify the and logic more directly:
perl -ne 'print if /string1/ && /string2/'
Your method was almost good, only missing the -w
grep -w 'string1\|string2' filename
You could try something like this:
(pattern1.*pattern2|pattern2.*pattern1)
The | operator in a regular expression means or. That is to say either string1 or string2 will match. You could do:
grep 'string1' filename | grep 'string2'
which will pipe the results from the first command into the second grep. That should give you only lines that match both.
And as people suggested perl and python, and convoluted shell scripts, here a simple awk approach:
awk '/string1/ && /string2/' filename
Having looked at the comments to the accepted answer: no, this doesn't do multi-line; but then that's also not what the author of the question asked for.
Don't try to use grep for this, use awk instead. To match 2 regexps R1 and R2 in grep you'd think it would be:
grep 'R1.*R2|R2.*R1'
while in awk it'd be:
awk '/R1/ && /R2/'
but what if R2 overlaps with or is a subset of R1? That grep command simply would not work while the awk command would. Lets say you want to find lines that contain the and heat:
$ echo 'theatre' | grep 'the.*heat|heat.*the'
$ echo 'theatre' | awk '/the/ && /heat/'
theatre
You'd have to use 2 greps and a pipe for that:
$ echo 'theatre' | grep 'the' | grep 'heat'
theatre
and of course if you had actually required them to be separate you can always write in awk the same regexp as you used in grep and there are alternative awk solutions that don't involve repeating the regexps in every possible sequence.
Putting that aside, what if you wanted to extend your solution to match 3 regexps R1, R2, and R3. In grep that'd be one of these poor choices:
grep 'R1.*R2.*R3|R1.*R3.*R2|R2.*R1.*R3|R2.*R3.*R1|R3.*R1.*R2|R3.*R2.*R1' file
grep R1 file | grep R2 | grep R3
while in awk it'd be the concise, obvious, simple, efficient:
awk '/R1/ && /R2/ && /R3/'
Now, what if you actually wanted to match literal strings S1 and S2 instead of regexps R1 and R2? You simply can't do that in one call to grep, you have to either write code to escape all RE metachars before calling grep:
S1=$(sed 's/[^^]/[&]/g; s/\^/\\^/g' <<< 'R1')
S2=$(sed 's/[^^]/[&]/g; s/\^/\\^/g' <<< 'R2')
grep 'S1.*S2|S2.*S1'
or again use 2 greps and a pipe:
grep -F 'S1' file | grep -F 'S2'
which again are poor choices whereas with awk you simply use a string operator instead of regexp operator:
awk 'index($0,S1) && index($0.S2)'
Now, what if you wanted to match 2 regexps in a paragraph rather than a line? Can't be done in grep, trivial in awk:
awk -v RS='' '/R1/ && /R2/'
How about across a whole file? Again can't be done in grep and trivial in awk (this time I'm using GNU awk for multi-char RS for conciseness but it's not much more code in any awk or you can pick a control-char you know won't be in the input for the RS to do the same):
awk -v RS='^$' '/R1/ && /R2/'
So - if you want to find multiple regexps or strings in a line or paragraph or file then don't use grep, use awk.
git grep
Here is the syntax using git grep with multiple patterns:
git grep --all-match --no-index -l -e string1 -e string2 -e string3 file
You may also combine patterns with Boolean expressions such as --and, --or and --not.
Check man git-grep for help.
--all-match When giving multiple pattern expressions, this flag is specified to limit the match to files that have lines to match all of them.
--no-index Search files in the current directory that is not managed by Git.
-l/--files-with-matches/--name-only Show only the names of files.
-e The next parameter is the pattern. Default is to use basic regexp.
Other params to consider:
--threads Number of grep worker threads to use.
-q/--quiet/--silent Do not output matched lines; exit with status 0 when there is a match.
To change the pattern type, you may also use -G/--basic-regexp (default), -F/--fixed-strings, -E/--extended-regexp, -P/--perl-regexp, -f file, and other.
Related:
How to grep for two words existing on the same line?
Check if all of multiple strings or regexes exist in a file
How to run grep with multiple AND patterns? & Match all patterns from file at once
For OR operation, see:
How do I grep for multiple patterns with pattern having a pipe character?
Grep: how to add an “OR” condition?
Found lines that only starts with 6 spaces and finished with:
cat my_file.txt | grep
-e '^ .*(\.c$|\.cpp$|\.h$|\.log$|\.out$)' # .c or .cpp or .h or .log or .out
-e '^ .*[0-9]\{5,9\}$' # numers between 5 and 9 digist
> nolog.txt
Let's say we need to find count of multiple words in a file testfile.
There are two ways to go about it
1) Use grep command with regex matching pattern
grep -c '\<\(DOG\|CAT\)\>' testfile
2) Use egrep command
egrep -c 'DOG|CAT' testfile
With egrep you need not to worry about expression and just separate words by a pipe separator.
grep ‘string1\|string2’ FILENAME
GNU grep version 3.1
Place the strings you want to grep for into a file
echo who > find.txt
echo Roger >> find.txt
echo [44][0-9]{9,} >> find.txt
Then search using -f
grep -f find.txt BIG_FILE_TO_SEARCH.txt
grep '(string1.*string2 | string2.*string1)' filename
will get line with string1 and string2 in any order
for multiline match:
echo -e "test1\ntest2\ntest3" |tr -d '\n' |grep "test1.*test3"
or
echo -e "test1\ntest5\ntest3" >tst.txt
cat tst.txt |tr -d '\n' |grep "test1.*test3\|test3.*test1"
we just need to remove the newline character and it works!
You should have grep like this:
$ grep 'string1' file | grep 'string2'
I often run into the same problem as yours, and I just wrote a piece of script:
function m() { # m means 'multi pattern grep'
function _usage() {
echo "usage: COMMAND [-inH] -p<pattern1> -p<pattern2> <filename>"
echo "-i : ignore case"
echo "-n : show line number"
echo "-H : show filename"
echo "-h : show header"
echo "-p : specify pattern"
}
declare -a patterns
# it is important to declare OPTIND as local
local ignorecase_flag filename linum header_flag colon result OPTIND
while getopts "iHhnp:" opt; do
case $opt in
i)
ignorecase_flag=true ;;
H)
filename="FILENAME," ;;
n)
linum="NR," ;;
p)
patterns+=( "$OPTARG" ) ;;
h)
header_flag=true ;;
\?)
_usage
return ;;
esac
done
if [[ -n $filename || -n $linum ]]; then
colon="\":\","
fi
shift $(( $OPTIND - 1 ))
if [[ $ignorecase_flag == true ]]; then
for s in "${patterns[#]}"; do
result+=" && s~/${s,,}/"
done
result=${result# && }
result="{s=tolower(\$0)} $result"
else
for s in "${patterns[#]}"; do
result="$result && /$s/"
done
result=${result# && }
fi
result+=" { print "$filename$linum$colon"\$0 }"
if [[ ! -t 0 ]]; then # pipe case
cat - | awk "${result}"
else
for f in "$#"; do
[[ $header_flag == true ]] && echo "########## $f ##########"
awk "${result}" $f
done
fi
}
Usage:
echo "a b c" | m -p A
echo "a b c" | m -i -p A # a b c
You can put it in .bashrc if you like.
grep -i -w 'string1\|string2' filename
This works for exact word match and matching case insensitive words ,for that -i is used
When the both strings are in sequence then put a pattern in between on grep command:
$ grep -E "string1(?.*)string2" file
Example if the following lines are contained in a file named Dockerfile:
FROM python:3.8 as build-python
FROM python:3.8-slim
To get the line that contains the strings: FROM python and as build-python then use:
$ grep -E "FROM python:(?.*) as build-python" Dockerfile
Then the output will show only the line that contain both strings:
FROM python:3.8 as build-python
If git is initialized and added to the branch then it is better to use git grep because it is super fast and it will search inside the whole directory.
git grep 'string1.*string2.*string3'
searching for two String and highlight only string1 and string2
grep -E 'string1.*string2|string2.*string1' filename | grep -E 'string1|string2'
or
grep 'string1.*string2\|string2.*string1' filename | grep -E 'string1\|string2'
ripgrep
Here is the example using rg:
rg -N '(?P<p1>.*string1.*)(?P<p2>.*string2.*)' file.txt
It's one of the quickest grepping tools, since it's built on top of Rust's regex engine which uses finite automata, SIMD and aggressive literal optimizations to make searching very fast.
Use it, especially when you're working with a large data.
See also related feature request at GH-875.