Writing Deskshell commands

Redirections

A redirection causes a UNIX file descriptor to be redirected to a different file. The following options are available:

< filename: the file is opened on descriptor 0, standard input, for reading only; it must already exist
> filename: the file is opened on descriptor 1, standard output, for writing, and is truncated; it is created if necessary
>> filename: the file is opened on descriptor 1, standard output, for append only; it is created if necessary

The following variants are available for each redirection. In each case ``<'' can be replaced by ``>'' or ``>>''.

< filename: read from filename
<[number] filename: read from filename on descriptor number
<[new=number]: make new a duplicate of number
<[number=]: close descriptor number

For example:

   for_info < $static_arg

displays the text from file $static_arg in a dialog box, and:

   gti 'Enter name:' > name

saves the user's name in a file name.