Using sed to remove string or paragraph between delimiter

sedtext processing

I would like to know who to remove a string or paragraph that are between ((( string )))

Lorem ipsum (((dolor sit amet))), consectetur adipiscing elit. Vestibulum aliquet fringilla est, dictum tempor nunc venenatis at. Sed nec velit sit amet velit cursus imperdiet. Vivamus tincidunt ut nunc quis euismod. Quisque sit amet lorem rhoncus, malesuada justo at, ullamcorper erat.

So "dolor sit amet" should not be in the return

Here's the cmd I have for now which detect the first ((( but then stop…

sed -e "/(((/,/)))/d" file.txt

Best Answer

Doing this for single line strings is very simple:

sed 's/((([^)]*)))//g' file

If you need it to deal with multiline strings, it gets more complex. One approach would be to use tr to replace all newlines with the null character (\0), make the substitution and translate back again:

tr '\n' '\0' < file | sed 's/((([^)]*)))//g' | tr '\0' '\n'

Alternatively, you could just use perl:

perl -0pe 's/\(\(\([^)]+\)\)\)//g;' file

The -0 causes perl to read the entire file into memory (this might be a problem for huge files), the -p means "print each line" but because of the -0, the "line" is actually the entire file. The s/// is the same idea as for sed.

Related Solutions

How to Remove a Paragraph from a File

Actually, sed can also take ranges. This command will delete all lines between Match user foo and the first empty line (inclusive):

$ sed '/Match user foo/,/^\s*$/{d}' file


Match user bar
        ChrootDirectory /NAS/bar.co.uk/
        ForceCommand internal-sftp
        AllowTcpForwarding no
        GatewayPorts no
        X11Forwarding no



Match user baz
        ChrootDirectory /NAS/baz.com/
        ForceCommand internal-sftp
        AllowTcpForwarding no
        GatewayPorts no
        X11Forwarding no

Personally, however, I would do this using perl's paragraph mode (-00) that has the benefit of removing the leading blank lines:

$ perl -00ne 'print unless /Match user foo/' file
Match user bar
        ChrootDirectory /NAS/bar.co.uk/
        ForceCommand internal-sftp
        AllowTcpForwarding no
        GatewayPorts no
        X11Forwarding no

Match user baz
        ChrootDirectory /NAS/baz.com/
        ForceCommand internal-sftp
        AllowTcpForwarding no
        GatewayPorts no
        X11Forwarding no

In both cases, you can use -i to edit the file in place (these will create a backup of the original called file.bak):

sed -i.bak '/Match user foo/,/^\s*$/{d}' file

perl -i.bak -00ne 'print unless /Match user foo/' file

Shell-Script – How to Delete Everything Until a Pattern and After Another Pattern from a Line

I'd use sed

sed 's/^.*\(consectetuer.*elit\).*$/\1/' file

Decoded the sed s/find/replace/ syntax:

s/^.* -- substitute starting at the beginning of the line (^) followed by anything (.*) up to...
\( - start a named block
consectetuer.*elit\. - match the first word, everything (.*) up to the last word (in this case, including the trailing (escaped)dot) you want to match
\) - end the named block
match everything else (.*) to the end of the line ($)
/ - end the substitute find section
\1 - replace with the name block between the $ and the $ above
/ - end the replace

Best Answer

Related Solutions

How to Remove a Paragraph from a File

Shell-Script – How to Delete Everything Until a Pattern and After Another Pattern from a Line

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