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16.1.5 Comparison of string APIs

This table summarizes the API functions available for strings, in POSIX and in Gnulib.

unibyte strings only	assume C locale	multibyte strings	multibyte strings with NULs	wide character strings	32-bit wide character strings
strlen	strlen	mbslen	string_desc_length	wcslen	u32_strlen
strnlen	strnlen	mbsnlen	–	wcsnlen	u32_strnlen, u32_mbsnlen
strcmp	strcmp	strcmp	string_desc_cmp	wcscmp	u32_strcmp
strncmp	strncmp	strncmp	–	wcsncmp	u32_strncmp
strcasecmp	strcasecmp	mbscasecmp	–	wcscasecmp	u32_casecmp
strncasecmp	strncasecmp	mbsncasecmp, mbspcasecmp	–	wcsncasecmp	u32_casecmp
strcoll	strcmp	strcoll	–	wcscoll	u32_strcoll
strxfrm	–	strxfrm	–	wcsxfrm	–
strchr	strchr	mbschr	string_desc_index	wcschr	u32_strchr
strrchr	strrchr	mbsrchr	string_desc_last_index	wcsrchr	u32_strrchr
strstr	strstr	mbsstr	string_desc_contains	wcsstr	u32_strstr
strcasestr	strcasestr	mbscasestr	–	–	–
strspn	strspn	mbsspn	–	wcsspn	u32_strspn
strcspn	strcspn	mbscspn	–	wcscspn	u32_strcspn
strpbrk	strpbrk	mbspbrk	–	wcspbrk	u32_strpbrk
strtok_r	strtok_r	mbstok_r	–	wcstok	u32_strtok
strsep	strsep	mbssep	–	–	–
strcpy	strcpy	strcpy	string_desc_copy	wcscpy	u32_strcpy
stpcpy	stpcpy	stpcpy	–	wcpcpy	u32_stpcpy
strncpy	strncpy	strncpy	–	wcsncpy	u32_strncpy
stpncpy	stpncpy	stpncpy	–	wcpncpy	u32_stpncpy
strcat	strcat	strcat	string_desc_concat	wcscat	u32_strcat
strncat	strncat	strncat	–	wcsncat	u32_strncat
free	free	free	string_desc_free	free	free
strdup	strdup	strdup	string_desc_copy	wcsdup	u32_strdup
strndup	strndup	strndup	–	–	–
mbswidth	mbswidth	mbswidth	–	wcswidth	c32swidth, u32_strwidth
strtol	strtol	strtol	–	–	–
strtoul	strtoul	strtoul	–	–	–
strtoll	strtoll	strtoll	–	–	–
strtoull	strtoull	strtoull	–	–	–
strtoimax	strtoimax	strtoimax	–	wcstoimax	–
strtoumax	strtoumax	strtoumax	–	wcstoumax	–
strtof	–	strtof	–	–	–
strtod	c_strtod	strtod	–	–	–
strtold	c_strtold	strtold	–	–	–
strfromf	–	strfromf	–	–	–
strfromd	–	strfromd	–	–	–
strfroml	–	strfroml	–	–	–
–	–	–	–	mbstowcs	mbstoc32s
–	–	–	–	mbsrtowcs	mbsrtoc32s
–	–	–	–	mbsnrtowcs	mbsnrtoc32s
–	–	–	–	wcstombs	c32stombs
–	–	–	–	wcsrtombs	c32srtombs
–	–	–	–	wcsnrtombs	c32snrtombs