jbc@ut-sally.UUCP (08/07/83)
UNIX* System V and 4.1C BSD
John Chambers
Office of Academic Computing & Biostatistics
University of Texas Medical Branch, Galveston
John Quarterman
Computation Center
University of Texas at Austin
{ihnp4,decvax!{eagle,allegra}}!ut-ngp!{jbc,jsq}
{jbc,jsq}@{ut-sally.UUCP,{utexas-11,utexas-780}.ARPA}
Presented at the July 1983 USENIX Conference in Toronto.
cO Copyright 1983 by the Regents of the University of Texas.
_A_B_S_T_R_A_C_T
This paper compares System V (the UNIX system which
Western Electric is currently licensing) and 4.1C BSD (the
final precursor to 4.2BSD, the research UNIX system
developed for DARPA by the University of California at
Berkeley), based on experience with both systems on a DEC
VAX-11/780.
The comparison covers several areas and includes
comments organized by manual section on numerous specific
features (languages, shells, text editing and formatting,
devices, etc.), plus more general and detailed discussions
of such topics as: installation and configuration; sources
and documentation; groups and identifiers; file systems;
interprocess communications; networks; performance
(including some tentative benchmarks); and vendor support.
Common features are mostly left to the manuals, in
order to better concentrate on differences. This is meant
to be a _q_u_a_l_i_t_a_t_i_v_e comparison, intended to serve only as a
guide for further study.
________
* UNIX is a Trademark of Bell Telephone Laboratories, Inc.
CONTENTS
1. Introduction....................................... 2
1.1 Intent....................................... 2
1.2 Format of the Paper.......................... 2
1.3 Disclaimers and Acknowledgments.............. 3
2. Manual Sections.................................... 3
2.1 Commands..................................... 3
2.1.1 User convenience..................... 3
2.1.2 Programming support environments..... 4
2.1.3 Shells............................... 6
2.1.4 Formatting and typesetting........... 6
2.1.5 Graphics............................. 7
2.1.6 Ingres............................... 7
2.1.7 Text editors......................... 7
2.1.8 Electronic mail...................... 8
2.1.9 Printing............................. 8
2.2 System Calls................................. 9
2.2.1 Vfork and fork....................... 9
2.2.2 Reboot............................... 9
2.2.3 Setpgrp.............................. 10
2.2.4 Group system calls................... 10
2.2.5 Ioctls............................... 10
2.2.6 Open and fcntl....................... 10
2.2.7 4.1C BSD file system calls........... 11
2.2.8 Timing............................... 12
2.2.9 IPC.................................. 12
2.3 Libraries and Subroutines.................... 12
2.3.1 Common Object File Format
routines............................. 12
2.3.2 Utmp routines........................ 12
2.3.3 F77 library.......................... 12
2.3.4 Knuth algorithms..................... 12
2.3.5 Software signals and matherr......... 13
2.3.6 Stdio buffering...................... 13
2.3.7 Printf............................... 13
2.3.8 String routines...................... 14
2.3.9 Network library...................... 14
2.4 Devices...................................... 14
2.4.1 Tty.................................. 14
2.4.2 DH-11................................ 14
2.4.3 KMC-11B.............................. 15
2.4.4 VPM.................................. 15
2.4.5 Synchronous terminal................. 15
2.4.6 BLIT................................. 15
2.4.7 Ptys................................. 15
2.4.8 Generalized disk driver.............. 15
2.4.9 Generalized tape driver.............. 16
2.5 File Formats................................. 16
- i -
2.5.1 A.out................................ 16
2.5.2 Ar................................... 16
2.5.3 Fs................................... 17
2.5.4 Termcap and descendants.............. 17
2.6 Games........................................ 17
2.6.1 System V games....................... 17
2.6.2 4.1C BSD ASCII graphics games........ 17
2.6.3 PDP-11 compatibility................. 18
2.7 Miscellany................................... 18
2.7.1 File system hierarchy................ 18
2.8 Maintenance.................................. 18
2.8.1 Init, getty, and login............... 18
2.8.2 Shutdown, halt, and reboot........... 19
2.8.3 Backups.............................. 19
2.8.4 Fsck, fsdb, etc...................... 20
2.8.5 Monitoring and debugging............. 20
2.8.6 Accounting........................... 21
3. Installation and Configuration..................... 21
3.1 Installation................................. 21
3.2 Configuration................................ 22
3.3 Transition................................... 23
4. Sources and Documentation.......................... 23
4.1 Make......................................... 24
4.2 SCCS......................................... 24
4.3 Sources...................................... 24
4.4 Documentation................................ 25
5. Groups and Identifiers............................. 25
5.1 Groups....................................... 25
5.2 Identifiers.................................. 26
6. File Systems....................................... 26
6.1 System V..................................... 27
6.1.1 New file system block size........... 27
6.1.2 Faster access........................ 27
6.2 4.1C BSD..................................... 27
6.2.1 Reimplementation for efficiency...... 27
6.2.2 Other modifications.................. 28
6.2.3 Extended (network) file system....... 28
7. Interprocess Communications (IPC).................. 29
7.1 System V..................................... 29
7.2 4.1C BSD..................................... 29
8. Networks........................................... 30
8.1 System V..................................... 30
8.1.1 X.25................................. 30
8.1.2 PCL network.......................... 30
8.1.3 NSC network.......................... 30
- ii -
8.1.4 RJE to IBM........................... 31
8.2 4.1C BSD..................................... 31
8.2.1 General networking framework......... 31
8.2.2 Variety of hardware and protocols
supported............................ 31
8.2.3 Internet (TCP/IP).................... 32
8.2.4 Berkeley protocols................... 32
8.3 UUCP......................................... 32
8.4 USENET....................................... 33
9. Performance........................................ 33
9.1 Some Qualitative Remarks..................... 33
9.1.1 Paging vs. swapping.................. 33
9.1.2 Terminal I/O......................... 34
9.2 Tentative Benchmarks......................... 34
9.2.1 Load simulation...................... 35
9.2.2 File system throughput............... 36
10. Vendor Support..................................... 36
10.1 Western Electric............................. 36
10.2 U.C. Berkeley................................ 36
10.3 DEC.......................................... 36
10.4 Third Parties................................ 37
10.4.1 OEMs................................. 37
10.4.2 Emulations........................... 37
10.4.3 Consultants.......................... 37
10.4.4 Authors.............................. 38
11. Conclusion......................................... 38
11.1 Selection Criteria........................... 38
11.2 Combinations................................. 38
11.3 Future Directions............................ 39
11.3.1 UNIX standards committee............. 39
11.3.2 Berkeley features and Bell........... 39
11.3.3 Bell licensing and Berkeley.......... 39
Appendix A: Terminology........................... 39
Appendix B: Load Simulation Job................... 41
- iii -
UNIX* System V and 4.1C BSD
John Chambers
Office of Academic Computing & Biostatistics
University of Texas Medical Branch, Galveston
John Quarterman
Computation Center
University of Texas at Austin
{ihnp4,decvax!{eagle,allegra}}!ut-ngp!{jbc,jsq}
{jbc,jsq}@{ut-sally.UUCP,{utexas-11,utexas-780}.ARPA}
Presented at the July 1983 USENIX Conference in Toronto.
cO Copyright 1983 by the Regents of the University of Texas.
_A_B_S_T_R_A_C_T
This paper compares System V1 (the UNIX system which
Western Electric is currently licensing) and 4.1C BSD2 (the
final precursor to 4.2BSD, the research UNIX system
developed for DARPA3 by the University of California at
Berkeley), based on experience with both systems on a DEC
VAX-11/7804.
The comparison covers several areas and includes
comments organized by manual section on numerous specific
features (languages, shells, text editing and formatting,
devices, etc.), plus more general and detailed discussions
__________
* UNIX is a Trademark of Bell Telephone Laboratories, Inc.
1. See Appendix A for the official names of Bell UNIX
Systems.
2. See Appendix A for details about Berkeley Software
Distributions (BSD).
3. Defense Advanced Research Projects Agency (DARPA),
formerly ARPA.
4. VAX, PDP, UNIBUS, MASSBUS, and SBI are Trademarks of
Digital Equipment Corporation (DEC).