NAME

cut − cut out selected fields of each line of a file

SYNOPSIS

cut −clist [file ...]
cut −flist [−dchar] [−s] [file ...]

DESCRIPTION

Use cut to cut out columns from a table or fields from each line of a file; in data base parlance, it implements the projection of a relation.  The fields as specified by list can be fixed length, i.e., character positions as on a punched card (−c option) or the length can vary from line to line and be marked with a field delimiter character like tab (−f option).  cut can be used as a filter; if no files are given, the standard input is used.  In addition, a file name of “−” explicitly refers to standard input. 

The meanings of the options are:

list A comma-separated list of integer field numbers (in increasing order), with optional − to indicate ranges [e.g., 1,4,7; 1−3,8; −5,10 (short for 1−5,10); or 3− (short for third through last field)]. 

−clist The list following −c (no space) specifies character positions (e.g., −c1−72 would pass the first 72 characters of each line). 

−flist The list following −f is a list of fields assumed to be separated in the file by a delimiter character (see −d ); e.g., −f1,7 copies the first and seventh field only.  Lines with no field delimiters will be passed through intact (useful for table subheadings), unless −s is specified. 

−dchar The character following −d is the field delimiter ( −f option only).  Default is tab. Space or other characters with special meaning to the shell must be quoted.

−s Suppresses lines with no delimiter characters in case of −f option.  Unless specified, lines with no delimiters will be passed through untouched. 

Either the −c or −f option must be specified. 

Use grep(1) to make horizontal “cuts” (by context) through a file, or paste(1) to put files together column-wise (i.e., horizontally). To reorder columns in a table, use cut and paste.

EXAMPLES

cut −d: −f1,5 /etc/passwd mapping of user IDs to names

name=`who am i | cut −f1 −d" "`
to set name to current login name. 

DIAGNOSTICS

ERROR:  line too long
A line can have no more than 1023 characters or fields, or there is no new-line character.

ERROR:  bad list for c/f option
Missing −c or −f option or incorrectly specified list. No error occurs if a line has fewer fields than the list calls for. 

ERROR:  no fields
The list is empty. 

ERROR:  no delimeter
Missing char on −d option. 

ERROR:  cannot handle multiple adjacent backspaces
Adjacent backspaces cannot be processed correctly.

WARNING:  cannot open <filename>
Either filename cannot be read or does not exist.  If multiple filenames are present, processing continues. 

SEE ALSO

grep(1), paste(1). 

September 02, 1992