Reference: sysopen
Author: Ellen Siever, Stephen Spainhour & Nathan Patwardhan
Date: 1999-07-02T01:38:43Z

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| Chapter 5 Function Reference |

## sysopen

    sysopen filehandle, filename, mode, [perms]

Opens the file given by filename and associates it with filehandle. This function calls `open(2)` with the parameters filename, mode, and perms.

The possible values and flag bits of the mode parameter are system-dependent; they are available via the Fcntl library module. However, for historical reasons, some values are universal: zero means read-only, one means write-only, and two means read/write.

If the file named by filename does not exist, and `sysopen` creates it (typically because mode includes the `O_CREAT` flag), then the value of perms specifies the permissions of the newly created file. If perms is omitted, the default value is `0666`, which allows read and write for all. This default is reasonable: see `umask`.

The FileHandle module provides a more object-oriented approach to `sysopen`. See also `open`.

Reference: syscall |  | Reference: sysread