Open System Services Shell and Utilities Reference Manual (G06.28+, H06.05+)

cat(1) OSS Shell and Utilities Reference Manual
NAME
cat - Concatenates or displays files
SYNOPSIS
cat [-benrstuv][- | file] ...
The cat command reads each specified file in sequence and writes it to standard output.
FLAGS
-b Omits line numbers from blank lines when -n is specified. If you specify the -b flag,
the -n flag is automatically invoked with it.
-e Same as the -v flag with a $ (dollar sign) character displayed at the end of each line.
-n Displays output lines preceded by line numbers, numbered sequentially from 1.
-r Replaces multiple consecutive empty lines with one empty line, so there is never more
than one empty line between lines containing characters.
-s Does not display a message if cat cannot find an input file. (Silent option.)
-t Same as the -v flag, with the tab character printed as <Ctrl-i> (ˆI).
-u Does not buffer output. Writes bytes from the input file to standard output without
delay as each is read.
-v Displays nonprinting characters so they are visible.
DESCRIPTION
The cat command is frequently used with > (redirection symbol) to concatenate the specified
files and write them to the specified destination. (See CAUTIONS.) cat is also used with >> to
append a file to another file.
If you do not specify a file or if you specify - (dash) instead of file, cat reads from standard input.
The cat command accepts multiple occurrences of - (dash) as a file argument.
EXAMPLES
1. To display the file notes,enter:
cat notes
If the file is longer than one screenful, it scrolls by too quickly to read. To display a file
one page at a time, use the more command.
2. To concatenate several files, enter:
cat section1.1 section1.2 section1.3 > section1
This creates a file named section1 that is a copy of section1.1 followed by section1.2
and section1.3.
3. To suppress error messages about files that do not exist, enter:
cat -s section2.1 section2.2 section2.3 > section2
If section2.1 does not exist, this command concatenates section2.2 and section2.3. Note
that the message goes to standard error, so it does not appear in the output file. The
result is the same if you do not use the -s flag except that cat displays the error message:
cat: cannot open section2.1
You may want to suppress this message with the -s flag when you use the cat command
in shell procedures.
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