NAME

ramfile - synthesise file

SYNOPSIS

ramfile file [ data ]

DESCRIPTION

Ramfile puts a virtual file in the name space at file, and services file requests on it. Data written to the file is stored in ramfile's memory; read requests return the previously stored data. If the optional data argument is provided, the file will initially contain that text. The parent directory of file must exist; ramfile creates a union mount on that directory, and if file previously existed, the synthesised file will hide it.

Ramfile uses sys-file2chan(2), which simplifies implementation but prevents it from knowing when the file has been truncated. Instead, it truncates the file on any write to the start of the file (offset 0), allowing cp(1) to copy in new contents, and text editors to edit it. Indeed, the file will be usable by all applications that do not rely on updating parts of the file in place, or if they do, do not update the start of the file.

SOURCE

/appl/cmd/ramfile.b

SEE ALSO

bind(1), sys-file2chan(2), srv(3), memfs(4)

BUGS

Ramfile cannot tell when the path has been unmounted; the only option is to kill(1) it.
The file always appears to have zero length to sys-stat(2), which prevents loading a Dis file from it.

RAMFILE(4 )

Rev:  Tue Mar 31 02:42:39 GMT 2015