Checking if output of a command contains a certain string in a shell script
Testing $? is an anti-pattern. if ./somecommand | grep -q ‘string’; then echo “matched” fi
grep
How to use sed/grep to extract text between two words?
GNU grep can also support positive & negative look-ahead & look-back: For your case, the command would be: echo “Here is a string” | grep -o -P ‘(?<=Here).*(?=string)’ If there are multiple occurrences of Here and string, you can choose whether you want to match from the first Here and last string or match them … Read more
Exclude .svn directories from grep [duplicate]
If you have GNU Grep, it should work like this: grep –exclude-dir=”.svn” If happen to be on a Unix System without GNU Grep, try the following: grep -R “whatever you like” *|grep -v “\.svn/*”
List files with certain extensions with ls and grep
Why not: ls *.{mp3,exe,mp4} I’m not sure where I learned it – but I’ve been using this.
How to get the part of a file after the first line that matches a regular expression
The following will print the line matching TERMINATE till the end of the file: sed -n -e ‘/TERMINATE/,$p’ Explained: -n disables default behavior of sed of printing each line after executing its script on it, -e indicated a script to sed, /TERMINATE/,$ is an address (line) range selection meaning the first line matching the TERMINATE … Read more
How to merge every two lines into one from the command line?
paste is good for this job: paste -d ” ” – – < filename
(grep) Regex to match non-ASCII characters?
This will match a single non-ASCII character: [^\x00-\x7F] This is a valid PCRE (Perl-Compatible Regular Expression). You can also use the POSIX shorthands: [[:ascii:]] – matches a single ASCII char [^[:ascii:]] – matches a single non-ASCII char [^[:print:]] will probably suffice for you.**
Grep characters before and after match?
3 characters before and 4 characters after $> echo “some123_string_and_another” | grep -o -P ‘.{0,3}string.{0,4}’ 23_string_and
How to remove the lines which appear on file B from another file A?
If the files are sorted (they are in your example): comm -23 file1 file2 -23 suppresses the lines that are in both files, or only in file 2. If the files are not sorted, pipe them through sort first… See the man page here
Is there a Pattern Matching Utility like GREP in Windows?
There is a command-line tool called FINDSTR that comes with all Windows NT-class operating systems (type FINDSTR /? into a Command Prompt window for more information) It doesn’t support everything grep does but it might be sufficient for your needs.