The shell shall execute commands from the file in the current
If file does not contain a slash, the shell shall use the search path
specified by PATH to find the directory containing file. Unlike
normal command search, however, the file searched for by the dot
utility need not be executable. If no readable file is found, a
non-interactive shell shall abort; an interactive shell shall write a
diagnostic message to standard error, but this condition shall not be
considered a syntax error.
Some older implementations searched the current directory for the file,
even if the value of PATH disallowed it. This behavior was omitted from
this volume of IEEE Std 1003.1-2001 due to concerns about
introducing the susceptibility to trojan horses that the user might be trying
to avoid by leaving dot out of PATH .
The KornShell version of dot takes optional arguments that are set to the
positional parameters. This is a valid extension that allows a dot
script to behave identically to a function.
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html