g.tempfile

NAME

g.tempfile - Creates a temporary file and prints the file name
(GRASS File Management Program)

SYNOPSIS

g.tempfile help
g.tempfile pid=value

DESCRIPTION

g.tempfile is designed for shell scripts that need to use large temporary files. GRASS provides a mechanism for temporary files that does not depend on /tmp. GRASS temporary files are created in the data base with the assumption that there will be enough space under the data base for large files. GRASS periodically removes temporary files that have been left behind by programs that failed to remove them before terminating.

g.tempfile creates an unique file and prints the name. The user is required to provide a process-id which will be used as part of the name of the file. Most Unix shells provide a way to get the process id of the current shell. For /bin/sh and /bin/csh this is $$. It is recommended that $$ be specified as the process-id for g.tempfile.

EXAMPLE

For /bin/sh scripts the following syntax should be used:

          temp1=`g.tempfile pid=$$`
          temp2=`g.tempfile pid=$$`

For /bin/csh scripts, the following can be used:

          set temp1=`g.tempfile pid=$$`
          set temp2=`g.tempfile pid=$$`

NOTES

Each call to g.tempfile creates a different (i.e. unique) name. Although GRASS does eventually get around to removing tempfiles that have been left behind, the programmer should make every effort to remove these files. They often get large and take up disk space. If you write /bin/sh scripts, learn to use the /bin/sh trap command. If you write /bin/csh scripts, learn to use the /bin/csh onintr command.

AUTHOR

Michael Shapiro, U.S. Army Construction Engineering Research Laboratory