delf(USP)

Name

delf : Remove the specified fields

       delf = delete fields

Synopsis

Usage   : delf f1 f2 ... <file>

          delf -d f1 f2 ... <string>

Version : Tue Jan  9 09:02:34 JST 2024

Edition : 3

Description

Removes the specified field from <file>.

(works oppositely to "self")

If the file name is omitted or "-" then the command

expects input on standard input.

Options

-d : Direct Mode

     Perform "delf" directly on specified "<string>".

Example 1

(Original Data)

$ cat data

0000000 Smith______ 50 F

0000001 Jones______ 50 F

0000003 Wilson_____ 26 F

0000004 Drake______ 40 M

0000005 Hawking____ 50 F

0000007 Newton_____ 42 F

0000008 Darwin_____ 50 F

0000009 Curie______ 68 F

0000010 Tesla______ 50 F

0000011 Chandra____ 55 F

$ delf 2 data      <- Remove the second field

0000000 50 F

0000001 50 F

0000003 26 F

0000004 40 M

0000005 50 F

0000007 42 F

0000008 50 F

0000009 68 F

0000010 50 F

0000011 55 F

Example 2

$ delf NF data

0000000 Smith______ 50

0000001 Jones______ 50

0000003 Wilson_____ 26

0000004 Drake______ 40

0000005 Hawking____ 50

0000007 Newton_____ 42

0000008 Darwin_____ 50

0000009 Curie______ 68

0000010 Tesla______ 50

0000011 Chandra____ 55

Example 3

$ delf 2/3 data

0000000 F

0000001 F

0000003 F

0000004 M

0000005 F

0000007 F

0000008 F

0000009 F

0000010 F

0000011 F

IMPORTANT

If there is no linefeed at the end of the file, then

a linefeed will be added at the end of the file to

complete the line.

Bug

Do not use files whose filename is entirely numeric.

If there exists a file whose filename is "10", then when you

run delf 1 10 --> it will delete the first field from the

file named "10" instead of deleting fields 1 through 10 from

standard input.

However, if you specify fields with only one digit (i.e. "2"), then

even if there is a file named "2" it will be ignored and "2" will

be considered the field designator.。