c - Which string manipulation functions should I use? -

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on windows/visual c environment there's wide number of alternatives doing same basic string manipulation tasks.

for example, doing string copy use:

  • strcpy, ansi c standard library function (crt)
  • lstrcpy, version included in kernel32.dll
  • strcpy, shell lightweight utility library
  • stringcchcopy/stringcbcopy, "safe string" library
  • strcpy_s, security enhanced version of crt

while understand these alternatives have historical reason, can choose consistent set of functions new code? , one? or should choose appropriate function case case?

first of all, let's review pros , cons of each function set:

ansi c standard library function (crt)

functions strcpy 1 , choice if developing portable c code. in windows-only project, may wise thing have separation of portable vs. os-dependent code.
these functions have assembly level optimization , therefore fast.
there drawbacks:

  • they have many limitations , therefore still have call functions other libraries or provide own versions
  • there archaisms infamous strncpy

kernel32 string functions

functions lstrcpy exported kernel32 , should used when trying avoid dependency crt. might want 2 reasons:

  • avoiding crt payload ultra lightweight executable (unusual these days not 10 years ago!)
  • avoiding initialization issues (if launch thread createthread instead of _beginthread).

moreover, kernel32 function could more optimized crt version: when executable run on windows 9 optimized core i13, kernel32 could use assembly-optimized version.

shell lightweight utility functions

here valid same considerations made kernel32 functions, added value of more complex functions. doubt actively maintained , skip them.

strsafe function

the stringcchcopy/stringcbcopy functions personal choice: designed, powerful, , surprisingly fast (i remember whitepaper compared performance of these functions crt equivalents).

security-enhanced crt functions

these functions have undoubted benefit of being similar ansi c equivalents, porting legacy code piece of cake. template-based version (of course, available when compiling c++). hope standardized. unfortunately have number of drawbacks:

  • although proposed standard, have been rejected non-windows community (probably because came microsoft)
  • when fail, don't return error code execute invalid parameter handler

conclusions

while personal favorite windows development strsafe library, advice use ansi c functions whenever possible, portable-code thing.

in real life, developed personalized portable library, prototypes similar security-enhanced crt functions (included powerful template based technique), relies on strsafe library on windows , on ansi c functions on other platforms.


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