The READ statement can be used to input data from internal files. When used for this purpose, the specifiers associated with it are as follows:
UNIT= <string>
<string> is a character variable. The keyword and equals sign are
optional if it is the first item in the list.
FMT= <string, label or *>
Specifies the format in which the data will be read. The keyword and equals
sign are optional if this is the second item in the list of specifiers.
IOSTAT= <variable>
<variable> will contain zero if the operation was successful, otherwise a
positive value to indicate an error, -1 to indicate EOF or -2 to indicate EOR.
ERR= <label>
<label> specifies a label to go to in the event of an error.
END= <label>
<label> specifies a label to go to on end of file.