Why C standards contain many unsafe functions, which are useless?

Question

Why C standards contain many unsafe functions, which are useless (in good programs them don't use) and harmful, for example getchar? Why C standard doesn't contain instead of them the useful functions, for example getch, and getche? It is only one of many examples...

UPD I confused: gets instead of getchar.

Because the input/output buffer hasn't to do with C, every operating system implements it's way. — Ramy Al Zuhouri, Dec 23 '12 at 16:49
Sounds like another person complaining about his betters not being perfect. C is arguably the most successful language of all time. — duffymo, Dec 23 '12 at 16:51
By "unsafe", OP means it doesn't perform a single unbuffered, raw-mode keypress read on the terminal like OP wants.... — R.. GitHub STOP HELPING ICE, Dec 23 '12 at 16:55
@duffymo I don't say that the C is bad. I don't understand why from time to time in the standard don't get rid from useless and don't add the useful. — Andrey Bushman, Dec 23 '12 at 16:56
It does get new ones. The recent C standard, C11, has "bound checking interfaces" in annex K (normative) which contains many "safe" functions with `_s` in the name. These might be to your liking. — Jens Gustedt, Dec 23 '12 at 16:57
I don't know what's wrong with getchar(), usually the most problematic function is scanf, but I don't know on what system he compiles. — Ramy Al Zuhouri, Dec 23 '12 at 16:58
@Bush `gets()` is just one unsafe function and it is deprecated in C99, so your premise about `standard contains many unsafe functions` is just plain wrong — qrdl, Dec 23 '12 at 21:28

Carl Norum · Accepted Answer · 2012-12-23T17:09:50.680

10

Do you mean gets? To not break old programs. The road to obsoleteness is long. And besides, it has been deprecated.

edited Dec 23 '12 at 17:09

answered Dec 23 '12 at 16:49

Carl Norum

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But why not added the `getch`, and `getche`? To whom do they hinder? Why to pull for itself a sore tail? Why not to cut off it? – Andrey Bushman Dec 23 '12 at 16:51
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@Bush: There are many good reasons not to add them. One is that many historical systems have functions by the same names which do completely different things; attempting to standardize one of those would be unacceptable to everybody else. Another reason is that these functions operate at a completely different level from stdio. The curses `getch` function, for example, works with curses key codes, not characters, and is not compatible with stdio buffering. – R.. GitHub STOP HELPING ICE Dec 23 '12 at 16:54
>Do you mean gets? @Carl Norum Yes, I am sorry, I confused with `gets`. – Andrey Bushman Dec 23 '12 at 17:02

score 2 · Answer 2 · answered Jul 26 '13 at 19:33

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gets is deprecated in C99 and has been removed in C11.

C11(ISO/IEC 9899:201x) Forward/6

removed the gets function ()

answered Jul 26 '13 at 19:33

Yu Hao

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Thank you, it is interesting. – Andrey Bushman Jul 27 '13 at 10:43

score 1 · Answer 3 · answered Dec 23 '12 at 19:49

You can't implement getch() [reading without buffering] on a teletype (terminal that looks like a typewriter). Or any type of terminal where the data is stored in the terminal until you hit enter.

There are functions that do this sort of things, but remember that C is a language that is supposed to "run on anything".

gets was part of the standard library many years ago, so it has to stay - otherwise, old code won't compile, and a lot of people like to use old code (because it's a lot of work to fix up 1000000 lines of messy code that used to work!)

Why C standards contain many unsafe functions, which are useless?

3 Answers3