1 TOLOWER(3C) Standard C Library Functions TOLOWER(3C) 2 3 4 5 NAME 6 tolower, tolower_l - transliterate upper-case characters to lower-case 7 8 SYNOPSIS 9 #include <ctype.h> 10 11 int tolower(int c); 12 13 int tolower_l(int c, locale_t loc); 14 15 16 DESCRIPTION 17 The tolower() function has as a domain of type int, the value of which 18 is representable as an unsigned char or the value of EOF. If the 19 argument has any other value, the argument is returned unchanged. If 20 the argument of tolower() represents an upper-case letter, and there 21 exists a corresponding lower-case letter (as defined by character type 22 information in the locale category LC_CTYPE), the result is the 23 corresponding lower-case letter. All other arguments in the domain are 24 returned unchanged. 25 26 The function tolower_l() behaves identically to tolower(), except 27 instead of operating in the current locale, it operates in the locale 28 specified by loc. 29 30 A macro form, _tolower() exists. It is defined for standards 31 conformance, particularly with legacy standards. It was deprecated in 32 POSIX 2008 (Issue 7), and its use is discouraged. The macro, on this 33 system, is just an alias for tolower(). 34 35 RETURN VALUES 36 On successful completion, tolower() returns the lower-case letter 37 corresponding to the argument passed. Otherwise, it returns the 38 argument unchanged. 39 40 ERRORS 41 No errors are defined. 42 43 ATTRIBUTES 44 See attributes(5) for descriptions of the following attributes: 45 46 +--------------------+-----------------+ 47 | ATTRIBUTE TYPE | ATTRIBUTE VALUE | 48 +--------------------+-----------------+ 49 |CSI | Enabled | 50 +--------------------+-----------------+ 51 |Interface Stability | Standard | 52 +--------------------+-----------------+ 53 |MT-Level | MT-Safe | 54 +--------------------+-----------------+ 55 56 SEE ALSO 57 newlocale(3C), setlocale(3C), uselocale(3C), attributes(5), 58 standards(5) 59 60 61 62 October 4, 2015 TOLOWER(3C)