NAME

cat, read − catenate files

SYNOPSIS

­cat [ ­file ...  ]
­read [ ­-m ] [ ­-n ­nline ] [ ­file ...  ]

DESCRIPTION

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

cat file

prints a file and

cat file1 file2 >file3

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

If no ­file is given, ­cat reads from the standard input.  Output is buffered in blocks matching the input. 

­Read copies to standard output exactly one line from the named file, default standard input. It is useful in interactive rc(1) scripts.

The ­-m flag causes it to continue reading and writing multiple lines until end of file; ­-n causes it to read no more than ­nline lines. 

­Read always executes a single ­write for each line of input, which can be helpful when preparing input to programs that expect line-at-a-time data.  It never reads any more data from the input than it prints to the output. 

SOURCE

­/sys/src/cmd/cat.c
­/sys/src/cmd/read.c

SEE ALSO

cp(1)

DIAGNOSTICS

­Read exits with status ­eof on end of file or, in the ­-n case, if it doesn’t read ­nlines lines. 

BUGS

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

Plan 9  —  April 17, 2005