Fortran has the equivalent of Unix file descriptors: By convention, many Fortran implementations use unit numbers UNIT=5 for stdin, UNIT=6 for stdout and UNIT=0 for stderr.
Fortran 提供類於 Unix 檔案描述子：UNIT=5 用於 stdin 、 UNIT=6 用於 stdout 和 UNIT=0 用於 stderr 。