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.
Contents
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.
Examples
Assuming a file named "file" containing the lines:
To output the fourth through tenth characters of each line:
To output the fifth field through the end of the line of each line using the colon character as the field delimiter:
(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:
(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:
Syntax
cut [-b] [-c] [-f list] [-n] [-d delim] [-s] [file]Flags which may be used include
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
cut -c1-66 would return the first 66 characters of a line