NAME

cat − catenate and print

SYNOPSIS

cat [ −u ] [ −n ] [ −s ] [ −v ] file ... 

DESCRIPTION

Cat reads each file in sequence and displays it on the standard output.  Thus

cat file

displays the file on the standard output, and

cat file1 file2 >file3

concatenates the first two files and places the result on the third. 

If no input file is given, or if the argument ‘−’ is encountered, cat reads from the standard input file.  Output is buffered in the block size recommended by stat(2) unless the standard output is a terminal, when it is line buffered.  The −u option makes the output completely unbuffered. 

The −n option displays the output lines preceded by lines numbers, numbered sequentially from 1.  Specifying the −b option with the −n option omits the line numbers from blank lines. 

The −s option crushes out multiple adjacent empty lines so that the output is displayed single spaced. 

The −v option displays non-printing characters so that they are visible.  Control characters print like ^X for control-x; the delete character (octal 0177) prints as ^?.  Non-ascii characters (with the high bit set) are printed as M- (for meta) followed by the character of the low 7 bits.  A −e option may be given with the −v option, which displays a ‘$’ character at the end of each line.  Specifying the −t option with the −v option displays tab characters as ^I. 

SEE ALSO

cp(1), ex(1), more(1), pr(1), tail(1)

BUGS

Beware of ‘cat a b >a’ and ‘cat a b >b’, which destroy the input files before reading them. 

4th Berkeley Distribution  —  May 5, 1986