User's manual. Section 1.

FLDS(1): print fields

USAGE

        usage: flds [-1Du] [-F sep] [-o sep] {-r range} {file}
        -1: fields separated by 1 run of the field delimiter string
        -D: debug
        -F sep: input field delimiter character(s) (or string under -1)
        -o sep: output field delimiter string
        -r range: print this range
        -u: use unix out

DESCRIPTION

Flds prints the requested fields for the given files. Fields are specified as ranges. A range may be a single line number, counting from 1, or a pair of start and end field numbers separated by a "," character. Negative field numbers count backwards from the end of the line (the last is -1 and so on).

Multiple ranges may be given. A missing start number in a range means 1, and a missing end number in a range means -1. If no range is given, "," is implied. And, when such range is indicated, all fields are printed, one line at a time.

By default the field separator is a run of blanks. Flag -F changes the set of runes used as field separators to its argument.

Flag -1 indicates that fields are separated exactly by one instance of the separator string. Such string defaults to a tabulator character in this case, unless -F says otherwise.

Fields are printed in the order indicated by the ranges given (first range gets printed first). Output fields are separated by default using a tab character or the sep string if -1 is used.

EXAMPLES

Print the first two fields and the last one from the ps output: 

        ; ps | rf | flds -u -r 1,2 -r -1

In a file with fields separated with ":", and, perhaps with empty fields, print just the first and third fields in reverse order: 

        ; ps | rf | flds -u -1F: -r 3 -r 1

Replace the field separator ":" with "," in all files under the current directory and update those files on disk: 

        ; gf , | flds -u -1F: -o, | pf -w

SOURCE

  • /zx/sys/src/clive/cmd/flds

User's manual. Section 1.