kopia lustrzana https://gitlab.com/sane-project/backends
118 wiersze
4.1 KiB
Plaintext
118 wiersze
4.1 KiB
Plaintext
Thu Mar 4 22:41:24 1999
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Here are a few rules that should help writing a SANE-conformant
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backend:
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* Please make sure that all global symbols exported from a SANE
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backend start with the prefix "sane" or "sanei". You can
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verify this by running GNU "nm" on the static library. For
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example:
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nm -g backend/.libs/libsane-hp.a
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would list all global symbols in the HP backend.
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* Please test a backend with "scanimage -T" (plus other options,
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as appropriate/necessary) as this will make sure that sane_read()
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always returns the correct amount of data etc.
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* Please test a backend not just with scanimage and xscanimage, but
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also with saned. Based on past experience, it is often the case
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that remote scanning can uncover subtle bugs. Note that you don't
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have to use two different machines to test "remote" scanning---you
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can use one and the same machine to test a backend via saned (just
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be sure to enable the "net" backend in dll.conf and follow the
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steps described in saned(1)).
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* Please follow the GNU coding standards. It's clear that the style
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outlined there is nobody's favorite, but it's much easier to
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maintain SANE if everybody follows more or less the same coding
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style. It also looks more professional. The GNU standards can be
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found at:
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http://www.gnu.org/prep/standards_toc.html
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ftp://ftp.gnu.org/pub/gnu/standards/standards.text
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Note that GNU emacs supports automatic indentation according to this
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standard. The command "indent -gnu" can be used to reformat
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existing sources according to this standard.
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* Please be curteous to programmer's with terminals that are 80
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characters wide. It's not difficult to avoid long lines, so please
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do so. Note that in ANSI C you can split long strings into pieces
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separated by white space. For example,
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"this is an awfully long string" can be written as "this is an "
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"awfully long string".
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* Please do not assume that `size_t' is `unsigned int'. On some
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systems, it's `unsigned long' and the size of this type may be
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bigger than that of an int (this is true for practially any of the
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64-bit systems). To print a variable of type size_t portably, cast
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the variable to u_long and print it with the %lu specifier. E.g.:
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size_t len;
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printf ("len=%lu\n", (u_long) len);
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* Please do not depend on GNU C specific features or, if you do, make
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the dependency conditional so other compilers will still be able to
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compile the files. In particular:
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- do not use C++ style comments (//-line comments)
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- do not declare dynamically sized automatic arrays; instead,
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use alloca() after including <lalloca.h>. For example:
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void
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func (int n)
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{
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char buf[n];
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}
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should be re-written as:
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#ifdef _AIX
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# include <lalloca.h> /* MUST come first for AIX! */
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#endif
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#include "sane/config.h"
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#include <lalloca.h>
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:
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void
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func (int n)
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{
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char *buf = alloca (n);
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}
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* Use #include "sane/..." to inlude the sane header files instead
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of #include <sane/...>. Otherwise problems with different installed
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SANE versions may occur.
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* Don't forget to #include "sane/config.h" in your backend before
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any other includes. If you use lalloca.h see above for the correct
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includes.
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* Please use sanei functions whenever possible (e.g.
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sanei_config_read()). This makes porting to other os/platforms much
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easier.
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* Don't use any #pragma directives---they're completely
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compiler-dependent.
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* Do make sure that your code is byte-order independent. This is
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particularly important for networking-related code and when dealing
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with non-textual data files.
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* Even if you haven't written a man-page for your backend yet, you
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*must* create a .desc file which describes it. Anytime you submit
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source code for your backend, you should include an update to the
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.desc file which reflects the new state of the backend.
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"template.desc." is a template for new .desc files. If you'd like
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to try parsing your creation to recreate the sane-backends webpage,
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look at "sane-desc.el" in the tools/ directory.
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* When your backend is included in the SANE distribution, add an entry
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to README and sane.lsm. The README entry should point to your
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documentation (man-page, website, readme).
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