The libg2c library currently has the following table to relate
error code numbers, returned in IOSTAT= variables, to messages.
This information should, in future versions of this document, be
expanded upon to include detailed descriptions of each message.
In line with good coding practices, any of the numbers in the
list below should not be directly written into Fortran
code you write.
Instead, make a separate INCLUDE file that defines
PARAMETER names for them, and use those in your code,
so you can more easily change the actual numbers in the future.
The information below is culled from the definition
of F_err in f/runtime/libI77/err.c in the
g77 source tree.
100: "error in format"
101: "illegal unit number"
102: "formatted io not allowed"
103: "unformatted io not allowed"
104: "direct io not allowed"
105: "sequential io not allowed"
106: "can't backspace file"
107: "null file name"
108: "can't stat file"
109: "unit not connected"
110: "off end of record"
111: "truncation failed in endfile"
112: "incomprehensible list input"
113: "out of free space"
114: "unit not connected"
115: "read unexpected character"
116: "bad logical input field"
117: "bad variable type"
118: "bad namelist name"
119: "variable not in namelist"
120: "no end record"
121: "variable count incorrect"
122: "subscript for scalar variable"
123: "invalid array section"
124: "substring out of bounds"
125: "subscript out of bounds"
126: "can't read file"
127: "can't write file"
128: "'new' file exists"
129: "can't append to file"
130: "non-positive record number"
131: "I/O started while already doing I/O"