インテル® Fortran コンパイラー 14.0 ユーザー・リファレンス・ガイド
Inquiry Intrinsic Function (Specific): Returns the index of the last command-line argument. It cannot be passed as an actual argument. This function can also be specified as IARG or NUMARG.
The result type is INTEGER(4). The result is the index of the last command-line argument, which is also the number of arguments on the command line. The command is not included in the count. For example, IARGC returns 3 for the command-line invocation of PROG1 -g -c -a.
IARGC returns a value that is 1 less than that returned by NARGS.