Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!nosc!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!hpda!hpcuhb!hpcllla!hpclisp!hpclcdb!cdb From: cdb@hpclcdb.HP.COM (Carl Burch) Newsgroups: comp.lang.fortran Subject: Fortran File Formats Survey Message-ID: <6690019@hpclcdb.HP.COM> Date: 6 Jul 88 21:52:00 GMT Organization: HP ITG/ISO Computer Language Lab Lines: 38 On systems like UN*X and MS-DOS with byte-stream file systems, the Fortran I/O library has to impose a data file format to support Fortran's record-oriented file model. On HP-UX, these take the following forms : Sequential Formatted file format : ASCII files delimited with the newline character (ACSII 10 decimal). Sequential Unformatted file format : Binary data preceded and followed by four bytes holding the record length (in bytes). The "green word" at the end is necessary to BACKSPACE the file correctly. Direct Formatted file format : ASCII fixed-length records not physically separated. Unwritten bytes in the record are padded with blanks. Direct Unformatted file format : Binary fixed-length records not physically separated. Unwritten bytes in the record are padded with zero bytes (ASCII Nulls). Bell's f77(1) compiler uses this scheme as well. On MS-DOS, (at least my copy of) Microsoft Fortran uses the above formats except that Direct Unformatted files are also padded with blanks and the Sequential Unformatted format uses only a one-byte "green word" to hold the length of each record. In the latter case, there is an escape value saying that the following record is full to the max (256?) and there will be following records. Given this much similarity, I wonder if we may have a de facto standard evolving here. If we could do something about the data format in binary files (e.g., the IEEE floating point format), it might be possible to use systems like NFS considerably more transparently than currently possible. I'd like examples of other byte-stream file systems' Fortran compilers' solutions to this problem. Are they as similar as those around my shop? Carl Burch