Unix command : text files playground

Combine several text files into a single one

cat file1 file2 file3 > newfile

Add more files to an existing document

cat file1 file2 file3 >> destfile

Delete lines in a text file that containing a specific string

grep -v “pattern” filename > filename2; mv filename2 filename

You can use grep. Lets say you want search in the file source_file , and the second file where you have the lines that you want to search from is input_file. Use

    grep -f input_file source_file > output_file

Let’s say your source_file is

    Humpty Dumpty sat on a wall
    Humpty Dumpty had a great fall
    All the King's horses and 
    All the Queen's men
    COuld not put Humpty together again

And input file is

    Humpty
    Queen

The your output fie would be

    Humpty Dumpty sat on a wall
    Humpty Dumpty had a great fall
    All the Queen's men
    COuld not put Humpty together again