Uniq reads the input
file comparing adjacent lines.
In the normal case, the second and succeeding copies
of repeated lines are
removed; the remainder is written on the output file.
Note that repeated lines must be adjacent
in order to be found;
see
sort(1).
If the
-u flag is used,
just the lines that are not repeated
in the original file are output.
The
-d option specifies that
one copy of just the repeated lines is to
be written.
The normal mode output is the union of the
-u and
-d mode outputs.
The
-c option supersedes
-u and
-d and generates
an output report in default style
but with each line preceded by a count of the
number of times it occurred.
The
letters and
chars arguments specify skipping an initial portion of each line
in the comparison:
|
|
|
-n |
The first
n fields
together with any blanks before each are ignored.
A field is defined as a string of non-space, non-tab characters
separated by tabs and spaces from its neighbors.
|
|
-f n
|
Same as
-n.
This option was introduced by POSIX.2.
|
|
+n |
The first
n characters are ignored.
Fields are skipped before characters.
|
|
-s n
|
Same as
+n.
This option was introduced by POSIX.2.
|
|