fprintffile

Fprintffile is a programming utility function that writes formatted text to a file. It combines printf-style formatting with standard file I/O, providing a convenient wrapper around lower-level writing operations. The function is described in various libraries and languages, but there is no single universal standard, so its exact signature may vary.

Typical usage involves directing output to a writable file handle. The first parameter is usually an open file handle or stream, the second is a format string, and any additional arguments supply values to be formatted according to the format specifiers in the string. In some implementations, a file path may be accepted as the first argument, with the function opening the file in write mode before performing the formatted write.

Parameters

- file: an open file handle or, in some variants, a file path that will be opened for writing.

- format: a string containing printf-style format specifiers.

- ...args: values to be formatted and inserted into the format string.

Return value and errors

- The function typically returns the number of characters written. On error, it may return a negative value or raise an exception, depending on the language and library. Some implementations relay I/O errors through the standard error handling mechanisms of the host language.

Notes

- Behavior with respect to newline characters, locale, and wide-character formatting follows the conventions of the underlying formatting and I/O facilities.

- It is important to ensure the file is opened in a suitable mode and that proper error checking is performed after the call.

See also

- fprintf, printf, sprintf, fwrite, open, close. Examples of similar patterns exist in language-specific libraries that offer formatted file output.