How to get the difference (only additions) between two files in linux
All of the below is copied directly from @TomOnTime's serverfault answer here:
Show lines that only exist in file a: (i.e. what was deleted from a)
comm -23 a b
Show lines that only exist in file b: (i.e. what was added to b)
comm -13 a b
Show lines that only exist in one file or the other: (but not both)
comm -3 a b | sed 's/^\t//'
(Warning: If file a
has lines that start with TAB, it (the first TAB) will be removed from the output.)
NOTE: Both files need to be sorted for "comm" to work properly. If they aren't already sorted, you should sort them:
sort <a >a.sortedsort <b >b.sortedcomm -12 a.sorted b.sorted
If the files are extremely long, this may be quite a burden as it requires an extra copy and therefore twice as much disk space.
Edit: note that the command can be written more concisely using process substitution (thanks to @phk for the comment):
comm -12 <(sort < a) <(sort < b)
You can try this
diff --changed-group-format='%>' --unchanged-group-format='' A1 A2
The options are documented in man diff
:
--GTYPE-group-format=GFMT format GTYPE input groups with GFMT
and:
LTYPE is 'old', 'new', or 'unchanged'. GTYPE is LTYPE or 'changed'.
and:
GFMT (only) may contain: %< lines from FILE1 %> lines from FILE2 [...]