FORTRAN Reference Manual

Utility Routines

FORTRAN Reference Manual—528615-001

15-31

CHECKLOGICALNAME Routine

The CHECKLOGICALNAME routine checks whether a saved ASSIGN message with a

given logical file name exists. It also returns the message serial number associated

with the saved ASSIGN message.

result

is an integer variable in which CHECKLOGICALNAME returns the result of the

operation. See Considerations.

logicalname

is a character expression of up to 63 characters that specifies the program unit

name and the logical file name in one of the following two forms:

programunit.filename

*.filename

If the logical file name does not include the program unit name component, specify

only the file name. In either case logicalname cannot have leading spaces. Any

character including and following a blank is ignored.

Considerations

Values returned by CHECKLOGICALNAME:

result = CHECKLOGICALNAME ( logicalname )

Return Value Meaning

<0 The negated message number of a previously saved ASSIGN

message with a logical file name that conflicts with the one

supplied. The logical file names conflict if only one is qualified or

if one is qualified by “*” and the other is qualified by a program

name. If there are more than one conflicting saved ASSIGN

messages, the negative of the message number of the first

ASSIGN message located is returned.

0 An ASSIGN message containing the specified logical file name

does not exist.

>0 Is the message number of the saved ASSIGN message with the

logical file name that matches the one supplied.