README
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- File : README
- Author : Richard A. O'Keefe.
- Updated: 30 April 1984
- Purpose: Explain the new strings package.
- The UNIX string libraries (described in the string(3) manual page)
- differ from UNIX to UNIX (e.g. strtok is not in V7 or 4.1bsd). Worse,
- the sources are not in the public domain, so that if there is a string
- routine which is nearly what you want but not quite you can't take a
- copy and modify it. And of course C programmers on non-UNIX systems
- are at the mercy of their supplier.
- This package was designed to let me do reasonable things with C's
- strings whatever UNIX (V7, PaNiX, UX63, 4.1bsd) I happen to be using.
- Everything in the System III manual is here and does just what the S3
- manual says it does. There are also lots of new goodies. I'm sorry
- about the names, but the routines do have to work on asphyxiated-at-
- birth systems which truncate identifiers. The convention is that a
- routine is called
- str [n] [c] <operation>
- If there is an "n", it means that the function takes an (int) "length"
- argument, which bounds the number of characters to be moved or looked
- at. If the function has a "set" argument, a "c" in the name indicates
- that the complement of the set is used. Functions or variables whose
- names start with _ are support routines which aren't really meant for
- general use. I don't know what the "p" is doing in "strpbrk", but it
- is there in the S3 manual so it's here too. "istrtok" does not follow
- this rule, but with 7 letters what can you do?
- I have included new versions of atoi(3) and atol(3) as well. They
- use a new primitive str2int, which takes a pair of bounds and a radix,
- and does much more thorough checking than the normal atoi and atol do.
- The result returned by atoi & atol is valid if and only if errno == 0.
- There is also an output conversion routine int2str, with itoa and ltoa
- as interface macros. Only after writing int2str did I notice that the
- str2int routine has no provision for unsigned numbers. On reflection,
- I don't greatly care. I'm afraid that int2str may depend on your "C"
- compiler in unexpected ways. Do check the code with -S.
- Several of these routines have "asm" inclusions conditional on the
- VaxAsm option. These insertions can make the routines which have them
- quite a bit faster, but there is a snag. The VAX architects, for some
- reason best known to themselves and their therapists, decided that all
- "strings" were shorter than 2^16 bytes. Even when the length operands
- are in 32-bit registers, only 16 bits count. So the "asm" versions do
- not work for long strings. If you can guarantee that all your strings
- will be short, define VaxAsm in the makefile, but in general, and when
- using other machines, do not define it.
- To use this library, you need the "strings.a" library file and the
- "strings.h" and "ctypes.h" header files. The other header files are
- for compiling the library itself, though if you are hacking extensions
- you may find them useful. General users really shouldn't see them.
- I've defined a few macros I find useful in "strings.h"; if you have no
- need for "index", "rindex", "streql", and "beql", just edit them out.
- On the 4.1bsd system I am using declaring all these functions 'extern'
- does not mean that they will all be loaded; but only the ones you use.
- When using lesser systems you may find it necessary to break strings.h
- up, or you could get by with just adding "extern" declarations for the
- functions you want as you need them. Many of these functions have the
- same names as functions in the "standard C library", by design as this
- is a replacement/reimplementation of part of that library. So you may
- have to talk the loader into loading this library first. Again, I've
- found no problems on 4.1bsd.
- You may wonder at my failure to provide manual pages for this code.
- For the things in V7, 4.?, or SIII, you should be able to use whichever
- manual page came with that system, and anything I might write would be
- so like it as to raise suspicions of violating AT&T copyrights. In the
- sources you will find comments which provide far more documentation for
- these routines than AT&T ever provided for their strings stuff, I just
- don't happen to have put it in nroff -man form. Had I done so, the .3
- files would have outbulked the .c files!
- These files are in the public domain. This includes getopt.c, which
- is the work of Henry Spencer, University of Toronto Zoology, who says of
- it "None of this software is derived from Bell software. I had no access
- to the source for Bell's versions at the time I wrote it. This software
- is hereby explicitly placed in the public domain. It may be used for
- any purpose on any machine by anyone." I would greatly prefer it if *my*
- material received no military use.