On Wed, Dec 18, 2013 at 11:36:12PM +0100, Maurice Quennet wrote: > Hello dev@, > > I was searching for a programming project so I looked into TODO and > picked printf. I hacked something up a few weeks ago, but I didn't > publish it until now, since I didn't have a man page yet and I was a > little busy (a patch follows at the end of the mail). > In the following I will tell a little bit about my implementation and > point out differences to OpenBSD's printf implementation (since I am a > OpenBSD user): > First for my `algorithm': There is nothing much to say. My > implementation simply skips through the format string until it finds a > '\' or a '%' and prints everything before that character. If a '\' was > found, the appropriate escape sequence is printed. If a '%' was found, > it skips forward until it finds a supported conversion specifier, and > passes everything starting from the '%' up until that point to printf(3) > (plus the approprietly converted command line argument). > And now for the differences: For a large part my implementation is > similar to OpenBSD's version. Both support the same escape sequences, > flags and conversion specifiers (which, as far as tested, behave the > same). The major difference is error handling. While OpenBSD's version > prints a warning to stderr and continues parsing its input, my version > exits immediately. Also, my implementation does not check the syntax of > the conversion specifier flags, but simply skips over them. > This is for the following two reasons: > 1.) printf(1) is mostly used for shell scripting, so I think it is ok to > expect the user to pass a well formed format string and to check his > arguments. Even if using a POSIX compliant printf(1), if you put in > garbage you will in return get garbage (or at least not what you > expected to get). > 2.) This way of error handling makes the code simpler/shorter. > For the man page: well, I really suck at writing man pages, especially > since my english is quite shaky. Also, while writing the man page, I > was wondering if it wasn't possible to simply use OpenBSD's man page > (with a few modifications) since both implementations seem to be largely > equivalent. > I have the feeling that I forgot to mention something, but, well, it > probably will come up again. Anyways I hope you like it. > > Best regards, > Maurice Quennet
People on this list need to learn about 'git format-patch' and 'git send-email'... -- William Giokas | KaiSforza | http://kaictl.net/ GnuPG Key: 0x73CD09CF Fingerprint: F73F 50EF BBE2 9846 8306 E6B8 6902 06D8 73CD 09CF
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