List-directed, sequential READ statements translate data from character to binary form by using the data types of the corresponding I/O list item to determine the form of the data. The translated data is then assigned to the entities in the I/O list in the order in which they appear, from left to right.
If a slash ( / ) is encountered during execution, the READ statement is terminated, and any remaining input list items are unchanged.
If the file is connected for unformatted I/O, list-directed data transfer is prohibited.
A list-directed external record consists of a sequence of values and value separators. A value can be any of the following:
Each constant must be a literal constant of type integer, real, complex, logical, or character; or a nondelimited character string. Binary, octal, hexadecimal, Hollerith, and named constants are not permitted.
In general, the form of the constant must be acceptable for the type of the list item. The data type of the constant determines the data type of the value and the translation from external to internal form. The following rules also apply:
A character string does not need delimiting apostrophes or quotation marks if the corresponding I/O list item is of type default character, and the following is true:
A nondelimited character string is terminated by the first blank, comma, slash, or end-of-record encountered. Apostrophes and quotation marks within nondelimited character strings are transferred as is.
A null value is specified by two consecutive value separators (such as ,,) or a nonblank initial value separator. (A value separator before the end of the record does not signify a null value.)
A null value indicates that the corresponding list element remains unchanged. A null value can represent an entire complex constant, but cannot be used for either part of a complex constant.
A value separator is any number of blanks, or a comma or slash, preceded or followed by any number of blanks. When any of these appear in a character constant, they are considered part of the constant, not value separators.
The end of a record is equivalent to a blank character, except when it occurs in a character constant. In this case, the end of the record is ignored, and the character constant is continued with the next record (the last character in the previous record is immediately followed by the first character of the next record).
Blanks at the beginning of a record are ignored unless they are part of a character constant continued from the previous record. In this case, the blanks at the beginning of the record are considered part of the constant.
Suppose the following statements are specified:
Then suppose the following external record is read:
CHARACTER*14 C DOUBLE PRECISION T COMPLEX D,E LOGICAL L,M READ (1,*) I,R,D,E,L,M,J,K,S,T,C,A,B
4 6.3 (3.4,4.2), (3, 2 ) , T,F,,3*14.6 ,'ABC,DEF/GHI''JK'/
The following values are assigned to the I/O list items:
|I/O List Item||Value Assigned|
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