xenial (1) dot.1posix.gz

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PROLOG
       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.


NAME
       dot — execute commands in the current environment


SYNOPSIS
       . file


DESCRIPTION
       The shell shall execute commands from the file in the current environment.

       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.


OPTIONS
       None.


OPERANDS
       See the DESCRIPTION.


STDIN
       Not used.


INPUT FILES
       See the DESCRIPTION.


ENVIRONMENT VARIABLES
       See the DESCRIPTION.


ASYNCHRONOUS EVENTS
       Default.


STDOUT
       Not used.


STDERR
       The standard error shall be used only for diagnostic messages.


OUTPUT FILES
       None.


EXTENDED DESCRIPTION
       None.


EXIT STATUS
       If  no  readable  file  was  found  or  if the commands in the file could not be parsed, and the shell is
       interactive (and therefore does not abort; see Section 2.8.1, Consequences of  Shell  Errors),  the  exit
       status shall be non-zero. Otherwise, return the value of the last command executed, or a zero exit status
       if no command is executed.


CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.


APPLICATION USAGE
       None.


EXAMPLES
       cat foobar
       foo=hello bar=world
       . ./foobar
       echo $foo $bar
       hello world


RATIONALE
       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  POSIX.1‐2008 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.


FUTURE DIRECTIONS
       None.


SEE ALSO
       Section 2.14, Special Built-In Utilities, return


       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers,  Inc
       and  The  Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .