cat 、tac、nl

NAME

cat - concatenate files and print on the standard output       /// [美] [kɑ:n´kæt?¸neit]  v./a.联系

SYNOPSIS

cat [OPTION] [FILE]...  

DESCRIPTION

Concatenate FILE(s), or standard input, to standard output.         ///将一个文件的内容连续输出

-A, --show-all

equivalent to -vET

-b, --number-nonblank

number nonblank output lines

-e

equivalent to -vE

-E, --show-ends

display $ at end of each line

-n, --number

number all output lines

-s, --squeeze-blank

never more than one single blank line

-t

equivalent to -vT

-T, --show-tabs

display TAB characters as ^I

-u

(ignored)

-v, --show-nonprinting                   ///显示看不到的特殊字符

use ^ and M- notation, except for LFD and TAB

--help

display this help and exit

--version

output version information and exit

With no FILE, or when FILE is -, read standard input.  

AUTHOR

Written by Torbjorn Granlund and Richard M. Stallman.  

REPORTING BUGS

Report bugs to <[e-mail]>.  

COPYRIGHT

Copyright © 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

SEE ALSO

The full documentation for cat is maintained as a Texinfo manual. If the info and cat programs are properly installed at your site, the command

info coreutils cat

should give you access to the complete manual.

NAME

tac - concatenate and print files in reverse  

SYNOPSIS

tac [OPTION]... [FILE]...  

DESCRIPTION

Write each FILE to standard output, last line first. With no FILE, or when FILE is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.

-b, --before

attach the separator before instead of after

-r, --regex

interpret the separator as a regular expression

-s, --separator=STRING

use STRING as the separator instead of newline

--help

display this help and exit

--version

output version information and exit

 

AUTHOR

Written by Jay Lepreau and David MacKenzie.  

REPORTING BUGS

Report bugs to <[e-mail]>.  

COPYRIGHT

Copyright © 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

SEE ALSO

The full documentation for tac is maintained as a Texinfo manual. If the info and tac programs are properly installed at your site, the command

info coreutils tac

should give you access to the complete manual.

 

NAME

nl - number lines of files  

SYNOPSIS

nl [OPTION]... [FILE]...  

DESCRIPTION

Write each FILE to standard output, with line numbers added. With no FILE, or when FILE is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.

-b, --body-numbering=STYLE

use STYLE for numbering body lines

-d, --section-delimiter=CC

use CC for separating logical pages

-f, --footer-numbering=STYLE

use STYLE for numbering footer lines

-h, --header-numbering=STYLE

use STYLE for numbering header lines

-i, --page-increment=NUMBER

line number increment at each line

-l, --join-blank-lines=NUMBER

group of NUMBER empty lines counted as one

-n, --number-format=FORMAT

insert line numbers according to FORMAT

-p, --no-renumber

do not reset line numbers at logical pages

-s, --number-separator=STRING

add STRING after (possible) line number

-v, --first-page=NUMBER

first line number on each logical page

-w, --number-width=NUMBER

use NUMBER columns for line numbers

--help

display this help and exit

--version

output version information and exit

By default, selects -v1 -i1 -l1 -sTAB -w6 -nrn -hn -bt -fn. CC are two delimiter characters for separating logical pages, a missing second character implies :. Type \\ for \. STYLE is one of:

a

number all lines

t

number only nonempty lines

n

number no lines

pREGEXP

number only lines that contain a match for REGEXP

FORMAT is one of:

ln

left justified, no leading zeros

rn

right justified, no leading zeros

rz

right justified, leading zeros

 

AUTHOR

Written by Scott Bartram and David MacKenzie.  

REPORTING BUGS

Report bugs to <[e-mail]>.  

COPYRIGHT

Copyright © 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

SEE ALSO

The full documentation for nl is maintained as a Texinfo manual. If the info and nl programs are properly installed at your site, the command

info coreutils nl

should give you access to the complete manual.

 

 

***********************eg************************

[test@zao2 ~]$ nl -b a -n rz -w 3 /etc/issue
001    Fedora release 12 (Constantine)
002    Kernel \r on an \m (\l)
003