Ubuntu – Comparing contents of two files

command linediff()

I have two files containing list of all files paths from two hard drives (supposed to be exactly the same), one of which I think has missing files. Both lists have the file path and size, but the lists are not in the same order (see example below).

Is there a command which can compare the difference between the two files and output the difference to a new file?

Example:

file1:

/docs/red
/docs/blue
/docs/yellow
/docs/green

file_2:

/docs/blue
/docs/green
/docs/red

Difference_File:

/docs/yellow

Best Answer

Use grep and no need sort them:

grep -Fxvf file2 file1 > diff_file

will return lines which are in file1 but not in file2 (lines missed in file2).

Related Solutions

Ubuntu – Comparing two text files

Try this command:

 grep -v -f file2.csv file1.csv > file3.csv

According to grep manual:

  -f FILE, --file=FILE
          Obtain  patterns  from  FILE,  one  per  line.   The  empty file
          contains zero patterns, and therefore matches nothing.   (-f  is
          specified by POSIX.)

  -v, --invert-match
          Invert the sense of matching, to select non-matching lines.  (-v
          is specified by POSIX.)

As Steeldriver said in his comment is better add also -x and -F that:

  -F, --fixed-strings
          Interpret PATTERN as a  list  of  fixed  strings,  separated  by
          newlines,  any  of  which is to be matched.  (-F is specified by
          POSIX.)
  -x, --line-regexp
          Select  only  those  matches  that exactly match the whole line.
          (-x is specified by POSIX.)

So, better command is:

 grep -xvFf file2.csv file1.csv > file3.csv

This command use file2.csv line as pattern and print line of file1.csv that doesn't match (-v).

Ubuntu – Diff command to compare files which are in first directory only

The --from-file option might be of use:

$ diff -r --brief foo bar
Files foo/a and bar/a differ
Files foo/b and bar/b differ
Files foo/c and bar/c differ
Only in bar: d
$ diff --brief --from-file=bar foo/*
Files bar/a and foo/a differ
Files bar/b and foo/b differ
Files bar/c and foo/c differ

So, in your case, it would be:

diff --brief --from-file=folder2 folder1/*

There's also the --unidirectional-new-file option:

--unidirectional-new-file
      treat absent first files as empty

With it:

$ diff /tmp/foo/ /tmp/bar -r --brief --unidirectional-new-file
Files /tmp/foo/a and /tmp/bar/a differ
Files /tmp/foo/b and /tmp/bar/b differ
Files /tmp/foo/c and /tmp/bar/c differ

Best Answer

Related Solutions

Ubuntu – Comparing two text files

Ubuntu – Diff command to compare files which are in first directory only

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