Concatenate and print files (POSIX)
Syntax:
cat [-c] [-n|-r] [-u] [file...]
Runs on:
QNX Neutrino, Linux, Microsoft Windows
Options:
- -c
- Compress sequences of multiple newline
characters into single newlines.
- -n
- Print line numbers, but don't restart the number for each new file.
- -r
- Print line numbers, restarting the number for each new file.
- -u
- Write unbuffered output. Data from the input file(s) is
written to the standard output
without delay as each file is read.
- file
- The pathname of an input file. If no files are
specified, the standard input is
used. If a file is the dash character (-),
cat reads from the standard input at that point in the
sequence.
Description:
The cat utility reads files in the order you specify
and writes their contents to
standard output.
Examples:
Write the contents of myfile to
standard output:
cat myfile
Concatenate doc1 and doc2
and write the result to doc.all:
cat doc1 doc2 > doc.all
Exit status:
- 0
- All input files were output successfully.
- >0
- An error occurred.
Caveats:
Because of the shell language mechanism
used to perform output redirection, a command such as:
cat doc doc.end > doc
causes the original data in doc to be lost. The file
doc is opened for write by the shell, and therefore
truncated to zero length, before cat is executed.