file-position

Set a position or get a current position for an open file.

file-position file-id <file id> \
    ( set <position> ) | ( get [ define ] <position> ) \
    [ status [ define ] <status> ]

file-position will set or get position for a file opened with open-file, where <file id> is an open file identifier.

If "set" clause is used, file position is set to <position>.

If "get" clause is used, file position is obtained in <position>, which can be created with optional "define".

The optional <status> in "status" clause will be VV_OKAY if set/get succeeded, or VV_ERR_POSITION if not. <status> can be created with optional "define".

Note that setting position past the last byte of file is okay for writing - in this case the bytes between the end of file and the <position> are filled with null-bytes when the write operation occurs.

Open file "testwrite" and set file byte position to 100, then obtain it later:

open-file "testwrite" file-id define nf
file-position file-id nf set 100
...
file-position file-id nf get define pos

See also open-file.

Files ( close-file   copy-file   delete-file   file-position   file_storage   file_uploading   lock-file   open-file   read-file   read-line   rename-file   stat-file   temporary_file   uniq-file   unlock-file   write-file  )  SEE ALL (documentation)