more than one cause, it *really* should have "int" as return value
for the error code.
-- Don't bother with error checking whether writing to stdout/stderr
+- Do not bother with error checking whether writing to stdout/stderr
worked.
- Do not log errors from "library" code, only do so from "main
- program" code. (With one exception: it's OK to log with DEBUG level
+ program" code. (With one exception: it is OK to log with DEBUG level
from any code, with the exception of maybe inner loops).
-- Always check OOM. There's no excuse. In program code, you can use
+- Always check OOM. There is no excuse. In program code, you can use
"log_oom()" for then printing a short message, but not in "library" code.
- Do not issue NSS requests (that includes user name and host name
lookups involve synchronously talking to services that we would need
to start up
-- Don't synchronously talk to any other service from PID 1, due to
+- Do not synchronously talk to any other service from PID 1, due to
risk of deadlocks
- Avoid fixed-size string buffers, unless you really know the maximum
size and that maximum size is small. They are a source of errors,
since they possibly result in truncated strings. It is often nicer
to use dynamic memory, alloca() or VLAs. If you do allocate fixed-size
- strings on the stack, then it's probably only OK if you either
+ strings on the stack, then it is probably only OK if you either
use a maximum size such as LINE_MAX, or count in detail the maximum
size a string can have. (DECIMAL_STR_MAX and DECIMAL_STR_WIDTH
macros are your friends for this!)
doing something wrong!
- Stay uniform. For example, always use "usec_t" for time
- values. Don't usec mix msec, and usec and whatnot.
+ values. Do not usec mix msec, and usec and whatnot.
- Make use of _cleanup_free_ and friends. It makes your code much
nicer to read!
{
}
- But it's OK if you don't.
+ But it is OK if you do not.
-- Don't write "foo ()", write "foo()".
+- Do not write "foo ()", write "foo()".
- Please use streq() and strneq() instead of strcmp(), strncmp() where applicable.
no speed benefit, and on calls like printf() "float"s get promoted
to "double"s anyway, so there is no point.
-- Don't invoke functions when you allocate variables on the stack. Wrong:
+- Do not invoke functions when you allocate variables on the stack. Wrong:
{
int a = foobar();
backwards!
- Think about the types you use. If a value cannot sensibly be
- negative, don't use "int", but use "unsigned".
+ negative, do not use "int", but use "unsigned".
-- Don't use types like "short". They *never* make sense. Use ints,
+- Do not use types like "short". They *never* make sense. Use ints,
longs, long longs, all in unsigned+signed fashion, and the fixed
size types uint32_t and so on, as well as size_t, but nothing else.
users then for ourselves! Note that assert() and assert_return()
really only should be used for detecting programming errors, not for
runtime errors. assert() and assert_return() by usage of _likely_()
- inform the compiler that he shouldn't expect these checks to fail,
+ inform the compiler that he should not expect these checks to fail,
and they inform fellow programmers about the expected validity and
range of parameters.
caching for any thread that is not the main thread. Use
is_main_thread() to detect whether the calling thread is the main
thread.
+
+- Option parsing:
+ - Do not print full help() on error, be specific about the error.
+ - Do not print messages to stdout on error.
+ - Do not POSIX_ME_HARDER unless necessary, i.e. avoid "+" in option string.
~ianmdlvl / elogind.git / blobdiff