Xref: utzoo comp.sys.ibm.pc:12005 comp.unix.questions:5667 comp.sys.att:2532 Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!think!husc6!spdcc!gnosys!gst From: gst@gnosys.UUCP (Gary S. Trujillo) Newsgroups: comp.sys.ibm.pc,comp.unix.questions,comp.sys.att Subject: Re: tar or cpio? Message-ID: <16@gnosys.UUCP> Date: 15 Feb 88 21:42:31 GMT References: <246@mancol.UUCP> <1629@cuuxb.ATT.COM> Reply-To: husc6!spdcc!gnosys!gst (Gary S. Trujillo) Followup-To: comp.unix.questions Organization: Home for the perpetually confused. Lines: 181 Keywords: tar,cpio,archivers Summary: USENIX Association's objections to current cpio In article <1629@cuuxb.ATT.COM> mmengel@cuuxb.UUCP (Marc W. Mengel) writes: | In article <246@mancol.UUCP> samperi@mancol.UUCP (Dominick Samperi) writes: | | I've heard that cpio will be used as the unix standard archiver, yet | | many people seem to prefer tar. | | ... | | I'd be interested to hear about any published standards for tar and/or | | cpio (AT&T, POSIX, etc.)... | | Well, you missed (about 1 month ago) a LONG discussion (TAR WARS (-:) in | comp.std.unix, which can be summarized (this off the top of my head, so | I won't try to credit the appropriate folks) as follows (tar and cpio | here refer to their respective archive formats): | | (deleted Marc's summary) | | These were the points discussed, and the tar format has been chosen (as | of the last I heard) for the POSIX (a.k.a IEEE 1003) standard. | | | Dominick Samperi, Manhattan College, NYC | | | -- | Marc Mengel | | attmail!mmengel | ...!{moss|lll-crg|mtune|ihnp4}!cuuxb!mmengel In reviewing my archives, I came across a copy of a message from the Usenix Association's representatives to the committee responsible for deciding on a standard for file interchange via magnetic tape. I thought readers of this discussion might find it interesting: | From husc6!ut-sally!std-unix Wed Aug 26 17:14:10 EDT 1987 | Article 114 of comp.std.unix: | Path: husc6!ut-sally!std-unix | From: jsq@usenix.uucp (John Quarterman) | Newsgroups: comp.std.unix | Subject: cpio format objections | Message-ID: <8832@ut-sally.UUCP> | Date: 24 Aug 87 23:24:22 GMT | Sender: std-unix@ut-sally.UUCP | Reply-To: jsq@usenix.uucp (John Quarterman) | Lines: 128 | Approved: fletcher@sally.utexas.edu (Guest Moderator, Fletcher Mattox) | | From: jsq@usenix.uucp (John Quarterman) | | cpio format objections Page 1 of 2 IEEE P1003.1 N.117 | 24 August 1987 | | John S. Quarterman | | Institutional Representative from USENIX | usenix!jsq | | | | Secretary, IEEE Standards Board | Attention: P1003 Working Group | 345 East 47th St. | New York, NY 10017 | | Cc: 1003.1 Technical Reviewers | for Section 10: for Rationale: | Stephen Dum Lorraine Kevra Hal Jespersen | tektronix!athena!steved attunix!kevra ucbvax!unisoft!hlj | | The USENIX Association ballots no on the test balloting of | IEEE 1003.1 Draft 11, objecting to the proposed inclusion of | cpio format, for the following reasons: | | 1. The need for extensions for symbolic links and | contiguous files has not been properly addressed. | Although three type codes are reserved, no indication | is given of what they should be used for. This does | not promote the need for those who implement such | extensions to implement them the same way. It is true | that the text of the standard cannot refer to symbolic | links or high performance files, because they are not | defined in the standard. But the USTAR format | indicates the use of its codes for those extensions | both by the name of the code given in the standard, | and by explicit recommendations in the Rationale. The | cpio proposal does neither. | | 2. The need for implementation-specific extensions that | do not conflict with present or future standard file | types has not been addressed. The USTAR format | addresses the problem by reserving 26 codes for | implementations to use as they see fit. The cpio | proposal does not address the problem at all. | | 3. The c_ino field of the cpio format is derived from the | UNIX inode number. Many implementations of cpio use | only 16 bits for this number, and thus cannot properly | resolve links noted in cpio archives that use more | bits for this number. Tar and USTAR formats do not | have this problem, because they do not use a number | like this to resolve links. While some USTAR file | types cannot be read by historical tar | implementations, an error will usually be produced. | This cpio problem will cause silent creation of | | | | | | | | cpio format objections Page 2 of 2 IEEE P1003.1 N.117 | | | | erroneous links, which is worse. | | 4. There are few, if any, distributions of UNIX systems | that do not include the tar program, which is | compatible with the POSIX USTAR format. There are | many UNIX systems that do not include cpio. | | 5. There is a public domain implementation of USTAR | format. There is no public domain implementation of | cpio format, with or without extensions. | | There should be one data interchange/archive format in IEEE | 1003.1. | | + The proposed cpio format is technically inferior to | USTAR format. | | + The program that cpio format is based on is not as | widely available as the one that USTAR format is based | on, and the same is true of the proposed cpio format | and of USTAR format, respectively. | | Therefore, the one format in the standard should be USTAR. | | Specific action: deny the cpio format proposal, and do not | include in the standard any references to that format or to | cpio. | | Thank you, | | | | John S. Quarterman | Texas Internet Consulting | 701 Brazos, Suite 500 | Austin, TX 78701-3243 | 512-320-9031 | | | | | | | | | | | | | | | | | | | | | | | Volume-Number: Volume 12, Number 21 | | Gary S. Trujillo {ihnp4,harvard,husc6,linus,ima,bbn,m2c}!spdcc!gnosys!gst Somerville, Massachusetts -- Gary S. Trujillo {ihnp4,harvard,husc6,linus,ima,bbn,m2c}!spdcc!gnosys!gst Somerville, Massachusetts