cut (Unix)

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For the more common operation related to copying and pasting, see Cut, copy, and paste.

In computing, cut is a Unix command line utility which is used to extract sections from each line of input — usually from a file. It is currently part of the GNU coreutils package and the BSD Base System. It first appeared in AT&T System III UNIX in 1982.[1][better source needed]

Extraction of line segments can typically be done by bytes (-b), characters (-c), or fields (-f) separated by a delimiter (-d — the tab character by default). A range must be provided in each case which consists of one of N, N-M, N- (N to the end of the line), or -M (beginning of the line to M), where N and M are counted from 1 (there is no zeroth value). Since version 6, an error is thrown if you include a zeroth value. Prior to this the value was ignored and assumed to be 1.


Assuming a file named "file" containing the lines:

the quick brown fox jumps over the lazy dog

To output the fourth through tenth characters of each line:

$ cut -c 4-10 file

To output the fifth field through the end of the line of each line using the colon character as the field delimiter:

$ cut -d ":" -f 5- file
the quick brown fox jumps over the lazy dog

(note that because the colon character is not found in the last line the entire line is shown)

Option -d specified a single character delimiter (in the example above it is a colon) which serves as field separator. Option -f which specifies range of fields included in the output (here fields range from five till the end). Option -d presupposes usage of option -f.

To output the third field of each line using space as the field delimiter:

$ cut -d " " -f 3 file

(Note that because the space character is not found in the first three lines these entire lines are shown.)

To separate two words having any delimiter:

$ line=process.processid
$ cut -d "." -f1 $line
$ cut -d "." -f2 $line


 cut [-b] [-c] [-f list] [-n] [-d delim] [-s] [file]

Flags which may be used include

Bytes; a list following -b specifies a range of bytes which will be returned, e.g. cut -b1-66 would return the first 66 bytes of a line. NB If used in conjunction with -n, no multi-byte characters will be split. NNB. -b will only work on input lines of less than 1023 bytes
Characters; a list following -c specifies a range of characters which will be returned, e.g. cut -c1-66 would return the first 66 characters of a line
Specifies a field list, separated by a delimiter
A comma separated or blank separated list of integer denoted fields, incrementally ordered. The - indicator may be supplied as shorthand to allow inclusion of ranges of fields e.g. 4-6 for ranges 4–6 or 5- as shorthand for field 5 to the end, etc.
Used in combination with -b suppresses splits of multi-byte characters
Delimiter; the character immediately following the -d option is the field delimiter for use in conjunction with the -f option; the default delimiter is tab. Space and other characters with special meanings within the context of the shell in use must be enquoted or escaped as necessary.
Bypasses lines which contain no field delimiters when -f is specified, unless otherwise indicated.
The file (and accompanying path if necessary) to process as input. If no file is specified then standard input will be used.

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