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## Standard error (stderr)

Most UNIX and GMT programs will on occasion write error messages. These are typically written to a separate data stream called stderr and can be redirected separately from the standard output (which goes to stdout). To redirect error messages we use

    UNIXprogram >& errors.log

When we want to save both program output and error messages to separate files we use the following syntax:

    (GMTprogram > output.d) >& errors.log