8.1 cut: Print selected parts of lines
cut writes to standard output selected parts of each line of each
input file, or standard input if no files are given or for a file name of
‘-’. Synopsis:
cut option... [file]...
In the table which follows, the byte-list, character-list,
and field-list are one or more numbers or ranges (two numbers
separated by a dash) separated by commas. Bytes, characters, and
fields are numbered starting at 1. Incomplete ranges may be
given: -m means ‘1-m’; ‘n-’ means
‘n’ through end of line or last field. The list elements
can be repeated, can overlap, and can be specified in any order; but
the selected input is written in the same order that it is read, and
is written exactly once.
The program accepts the following options. Also see Common options.
- ‘-b byte-list’
- ‘--bytes=byte-list’
- Select for printing only the bytes in positions listed in
byte-list. Tabs and backspaces are treated like any other
character; they take up 1 byte. If an output delimiter is specified,
(see the description of --output-delimiter), then output that
string between ranges of selected bytes.
- ‘-c character-list’
- ‘--characters=character-list’
- Select for printing only the characters in positions listed in
character-list. The same as -b for now, but
internationalization will change that. Tabs and backspaces are
treated like any other character; they take up 1 character. If an
output delimiter is specified, (see the description of
--output-delimiter), then output that string between ranges
of selected bytes.
- ‘-f field-list’
- ‘--fields=field-list’
- Select for printing only the fields listed in field-list.
Fields are separated by a TAB character by default. Also print any
line that contains no delimiter character, unless the
--only-delimited (-s) option is specified.
Note awk supports more sophisticated field processing,
and by default will use (and discard) runs of blank characters to
separate fields, and ignore leading and trailing blanks.
awk '{print $2}' # print the second field
awk '{print $NF-1}' # print the penultimate field
awk '{print $2,$1}' # reorder the first two fields
In the unlikely event that awk is unavailable,
one can use the join command, to process blank
characters as awk does above.
join -a1 -o 1.2 - /dev/null # print the second field
join -a1 -o 1.2,1.1 - /dev/null # reorder the first two fields
- ‘-d input_delim_byte’
- ‘--delimiter=input_delim_byte’
- With -f, use the first byte of input_delim_byte as
the input fields separator (default is TAB).
- ‘-n’
- Do not split multi-byte characters (no-op for now).
- ‘-s’
- ‘--only-delimited’
- For -f, do not print lines that do not contain the field separator
character. Normally, any line without a field separator is printed verbatim.
- ‘--output-delimiter=output_delim_string’
- With -f, output fields are separated by output_delim_string.
The default with -f is to use the input delimiter.
When using -b or -c to select ranges of byte or
character offsets (as opposed to ranges of fields),
output output_delim_string between non-overlapping
ranges of selected bytes.
- ‘--complement’
- This option is a GNU extension.
Select for printing the complement of the bytes, characters or fields
selected with the -b, -c or -f options.
In other words, do not print the bytes, characters or fields
specified via those options. This option is useful when you have
many fields and want to print all but a few of them.
An exit status of zero indicates success,
and a nonzero value indicates failure.