Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.55 INQUIRE Statement
The INQUIRE statement is used to ask about certain properties of a named file or its connection to a
particular unit. There are two forms of the INQUIRE statement; inquire by file name and inquire by unit.
2.55.1 INQUIRE by FILE
INQUIRE (iflist)
where:
iflist
includes the FILE= specifier and may include at most one of each of the inquiry specifiers
listed below. Specifiers are separated by commas. The FILE= specifier has the form
FILE = fin
where fin is a character expression whose value when trailing blanks are removed is the
name of a file being inquired about. The file need not exist or be connected to a unit.
Example:
LOGICAL EX, OD
INTEGER NUM
INQUIRE( FILE=’ROLL’,EXIST=EX,OPENED=OD,NUMBER=NUM )
In the above example, information is requested on the file PAYROLL. In particular, we want to know if it
exists, whether it is connected to a unit, and what the unit number is (if it is indeed connected).
2.55.2 INQUIRE by UNIT
INQUIRE (iulist)
where:
iulist
includes the UNIT= specifier and may include at most one of each of the inquiry specifiers
listed below. Specifiers are separated by commas. The UNIT= specified has the form
[UNIT =] u
where u is an external unit identifier. An external unit identifier is a non-negative integer
expression. If the optional UNIT= specifier is omitted then the specifier must be the first
item in the list of specifiers.
INQUIRE Statement 93