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fprintf

fprintf refNum,formatStr [, parameter]...​

The fprintf operation prints formatted output to a text file.

Parameters​

refNum is a file reference number from the Open operation used to create the file.

formatStr is the format string, as used by the printf operation.

parameter varies depending on formatStr.

Details​

If refNum is 1, Igor will print to the history area instead of to a file, as if you used printf instead of fprintf. This is provided for debugging purposes.

A zero value of refNum is used in conjunction with ActiveX Automation. The data that would normally be written to a file is appended to the ActiveX Automation result packet.

The fprintf operation supports numeric (real only) and string fields from structures. All other structure field types cause a compile error.

Output to Standard Streams​

If refNum is -1, Igor prints to the standard output stream (stdout).

If refNum is -2, Igor prints to the standard error stream (stderr).

This feature was added in Igor Pro 8.00. It is useful primarily when you launch Igor from a custom application. The application may be able to capture Igor's standard stream output.

stdout and stderr output is not visible even if Igor is started from the command line.

See Also​

The printf operation for complete format and parameter descriptions and Creating Formatted Text in the Advanced Topics help file. Also see Open about files.