NAME

       fg - run jobs in the foreground

SYNOPSIS

       fg [job_id]

DESCRIPTION

       If  job  control  is  enabled (see the description of set -m), the fg utility shall move a
       background job from the current environment (see Shell Execution Environment  )  into  the
       foreground.

       Using  fg  to place a job into the foreground shall remove its process ID from the list of
       those "known in the current shell execution environment''; see Asynchronous Lists .

OPTIONS

       None.

OPERANDS

       The following operand shall be supported:

       job_id Specify the job to be run as a foreground job. If no job_id operand is  given,  the
              job_id  for  the job that was most recently suspended, placed in the background, or
              run as a background job shall be used. The format of job_id  is  described  in  the
              Base Definitions volume of IEEE Std 1003.1-2001, Section 3.203, Job Control Job ID.

STDIN

       Not used.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of fg:

       LANG   Provide  a  default  value for the internationalization variables that are unset or
              null. (See the  Base  Definitions  volume  of  IEEE Std 1003.1-2001,  Section  8.2,
              Internationalization Variables for the precedence of internationalization variables
              used to determine the values of locale categories.)

       LC_ALL If set to  a  non-empty  string  value,  override  the  values  of  all  the  other
              internationalization variables.

       LC_CTYPE
              Determine  the  locale for the interpretation of sequences of bytes of text data as
              characters (for  example,  single-byte  as  opposed  to  multi-byte  characters  in
              arguments).

       LC_MESSAGES
              Determine  the  locale  that  should  be  used to affect the format and contents of
              diagnostic messages written to standard error.

       NLSPATH
              Determine the location of message catalogs for the processing of LC_MESSAGES .

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       The fg utility shall write the command line of the job to standard output in the following
       format:

              "%s\n", <command>

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0     Successful completion.

       >0     An error occurred.

CONSEQUENCES OF ERRORS

       If  job  control  is disabled, the fg utility shall exit with an error and no job shall be
       placed in the foreground.

       The following sections are informative.

APPLICATION USAGE

       The fg utility does not work as expected when it is operating in its own utility execution
       environment  because  that  environment  has  no  applicable  jobs  to manipulate. See the
       APPLICATION USAGE section for bg . For this reason, fg is generally implemented as a shell
       regular built-in.

EXAMPLES

       None.

RATIONALE

       The  extensions  to the shell specified in this volume of IEEE Std 1003.1-2001 have mostly
       been based on features provided by the KornShell. The job control features provided by bg,
       fg,  and  jobs  are  also  based  on  the  KornShell. The standard developers examined the
       characteristics of the C shell versions of these  utilities  and  found  that  differences
       exist.  Despite  widespread  use  of the C shell, the KornShell versions were selected for
       this volume of IEEE Std 1003.1-2001 to maintain a degree of uniformity with  the  rest  of
       the KornShell features selected (such as the very popular command line editing features).

FUTURE DIRECTIONS

       None.

SEE ALSO

       Asynchronous Lists , Shell Execution Environment , bg , kill() , jobs , wait()

COPYRIGHT

       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 .