# $$\text{FileSeek}$$¶

You can use the $$\text{FileSeek}$$ function to position a file pointer in a file.

You can use the \fileseek backslash command to insert this function.

The following variants of this function are available:

• $$\text{boolean } \text{FileSeek} \left ( \text{<file number>}, \text{<offset>} \right )$$

The $$\text{<file number>}$$ parameter is an integer value returned by one of the $$\text{FileOpen}\ldots$$ functions. The $$\text{<offset>}$$ parameter indicates the byte offset into the file where you want the file pointer to be placed. The file offset is zero based rather than one based.

The $$\text{FileSeek}$$ function returns true on success or false on error.

After using the $$\text{FileSeek}$$ function, you will generally want to call one of the $$\text{FileRead}\ldots$$ or $$\text{FileWrite}\ldots$$ functions to read or update the file contents.

The Figure 135 shows how you can use the $$\text{FileOpenWrite}$$ function.

Note

The $$\text{FileRead}\ldots$$ and $$\text{FileWrite}\ldots$$ functions will advance the file pointer so you do not need to use the $$\text{FileSeek}$$ function to read or write sequentially through a file.

Note

The $$\text{FileOpenRead}$$ and $$\text{FileOpenWriteTruncate}$$ functions will automatically position the file pointer to offset 0. The $$\text{FileOpenWrite}$$ function will place the file pointer at the end of the file.