Access the C Standard Library

Standard library C functions exposed to Python.

Most of the functions in the C standard library are included in a single shared libraryAn executable file containing definitions (function/variables/...) but no main method. which is part of your operating system (see the table below). The cslug.stdlib module loads and exposes the contents of this library to be directly called from Python.

Platform	Library/location
Linux	A combination of libc.so and, if present and not just aliases of libc.so, libm.so and libdl.so.
Windows >11	C:\Windows\system32\ucrt.dll
Windows 7-10	The somewhat barren C:\Windows\system32\msvcrt.dll.
macOS	libc.dylib.
MSYS2	msys-2.0.dll, requires cslug >= 0.5.1 for newer versions of Python.
Cygwin	cygwin1.dll, requires cslug >= 0.4.0.
*BSD	A combination of libc.so and libm.so.
Android	A combination of libc.so and libm.so.
Solaris	A combination of libc.so and libm.so.
Omnios	A combination of libc.so and libm.so.

Not every function is made available. A function is excluded if:

• It is not available on your current platform.

• It uses types which are unavailable to ctypes.

• It's a macro, meaning that it's refactored away at compile time and doesn't exist in any binariesNickname for shared library. format.

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The functions on this page are grouped by the header file they are included from. Each function has a row of icons corresponding to the platforms that it can be found on. See the key below for which platform each icon symbolises:

• Android

• Cygwin (UNIX emulator for Windows).

• DragonFlyBSD

• FreeBSD

• Linux distributions using GNU libc (i.e. the vast majority of them)

• macOS (x86_64 or arm64)

• MSYS2 (another UNIX emulator for Windows)

• Linux distributions using musl libc (most famously Alpine)

• NetBSD

• Omnios

• OpenBSD

• Solaris

• Windows 7 to 10 (using the MSVC runtime)

• Windows 11 (using the new Universal C Runtime)

Credits: The textual descriptions on this page were taken from here.

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assert.h

Functions defined with #include <assert.h>.

void assert(int expression);

Prints a diagnostic message and ends the program if the expression is false.

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ctype.h

Functions defined with #include <ctype.h>.

int isalnum(int c);

Tests if c is alphanumeric.

int isalpha(int c);

Tests if c is alphabetic.

int isascii(int c);

Tests if c is within the 7-bit US-ASCII range.

int isblank(int c);

Tests if c is a blank or tab character.

int iscntrl(int c);

Tests if c is a control character.

int isdigit(int c);

Tests if c is a decimal digit.

int isgraph(int c);

Tests if c is a printable character excluding the space.

int islower(int c);

Tests if c is a lowercase letter.

int isprint(int c);

Tests if c is a printable character including the space.

int ispunct(int c);

Tests if c is a punctuation character.

int isspace(int c);

Tests if c is a whitespace character.

int isupper(int c);

Tests if c is an uppercase letter.

int toascii(int c);

Converts c to a character in the 7-bit US-ASCII character set.

int tolower(int c);

Converts c to lowercase.

int toupper(int c);

Converts c to uppercase.

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locale.h

Functions defined with #include <locale.h>.

struct lconv *localeconv(void);

Formats numeric quantities in struct lconv according to the current locale.

char *setlocale(int category, const char *locale);

Changes or queries variables defined in the locale.

struct wcslconv *wcslocaleconv(void);

Formats numeric quantities in struct wcslconv according to the current locale.

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math.h

Functions defined with #include <math.h>.

double acos(double x);

Calculates the arc cosine of x.

double asin(double x);

Calculates the arc sine of x.

double atan(double x);

Calculates the arc tangent of x.

double atan2(double y, double x);

Calculates the arc tangent of y/x.

double ceil(double x);

Calculates the double value representing the smallest integer that is greater than or equal to x.

double cos(double x);

Calculates the cosine of x.

double cosh(double x);

Calculates the hyperbolic cosine of x.

double erf(double x);

Calculates the error function of x.

double erfc(double x);

Calculates the error function for large values of x.

double exp(double x);

Calculates the exponential function of a floating-point argument x.

double fabs(double x);

Calculates the absolute value of a floating-point argument x.

double floor(double x);

Calculates the floating-point value representing the largest integer less than or equal to x.

double fmod(double x, double y);

Calculates the floating-point remainder of x/y.

double frexp(double x, int *expptr);

Separates a floating-point number into its mantissa and exponent.

double gamma(double x);

Computes the Gamma Function

double hypot(double side1, double side2);

Calculates the hypotenuse of a right-angled triangle with sides of length side1 and side2.

double j0(double x);

Calculates the Bessel function value of the first kind of order 0.

double j1(double x);

Calculates the Bessel function value of the first kind of order 1.

double jn(int n, double x);

Calculates the Bessel function value of the first kind of order n.

double ldexp(double x, int exp);

Returns the value of x multiplied by (2 to the power of exp).

double log(double x);

Calculates the natural logarithm of x.

double log10(double x);

Calculates the base 10 logarithm of x.

double modf(double x, double *intptr);

Breaks down the floating-point value x into fractional and integral parts.

double nextafter(double x, double y);

Calculates the next representable value after x in the direction of y.

long double nextafterl(long double x, long double y);

Calculates the next representable value after x in the direction of y.

double nexttoward(double x, long double y);

Calculates the next representable value after x in the direction of y.

long double nexttowardl(long double x, long double y);

Calculates the next representable value after x in the direction of y.

double pow(double x, double y);

Calculates the value x to the power y.

double sin(double x);

Calculates the sine of x.

double sinh(double x);

Calculates the hyperbolic sine of x.

double sqrt(double x);

Calculates the square root of x.

double tan(double x);

Calculates the tangent of x.

double tanh(double x);

Calculates the hyperbolic tangent of x.

double y0(double x);

Calculates the Bessel function value of the second kind of order 0.

double y1(double x);

Calculates the Bessel function value of the second kind of order 1.

double yn(int n, double x);

Calculates the Bessel function value of the second kind of order n.

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regex.h

Functions defined with #include <regex.h>.

int regcomp(regex_t *preg, const char *pattern, int cflags);

Compiles the source regular expression pointed to by pattern into an executable version and stores it in the location pointed to by preg.

size_t regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size);

Finds the description for the error code errcode for the regular expression preg.

int regexec(const regex_t *preg, const char *string, size_t nmatch, regmatch_t *pmatch, int eflags);

Compares the null-ended string string against the compiled regular expression preg to find a match between the two.

void regfree(regex_t *preg);

Frees any memory that was allocated by regcomp to implement the regular expression preg.

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signal.h

Functions defined with #include <signal.h>.

int raise(int sig);

Sends the signal sig to the running program.

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stdarg.h

Functions defined with #include <stdarg.h>.

void va_start(va_list *arg_ptr, variable_name*);

Initializes arg_ptr for subsequent use by va_arg and va_end.

int vfprintf(FILE *stream, const char *format, *va_list arg_ptr*);

Formats and prints characters to the output stream using a variable number of arguments.

int vfwprintf(FILE *stream, const wchar_t *format, *va_list arg*);

Equivalent to fwprintf, except that the variable argument list is replaced by arg.

int vfwscanf(FILE *stream, const wchar_t *format, *va_list arg_ptr*);

Reads wide data from a specified stream into locations given by a variable number of arguments.

int vscanf(const char *format, *va_list arg_ptr*);

Reads data from stdin into locations given by a variable number of arguments.

int vsscanf(const char*buffer, const char *format, *va_list arg_ptr*);

Reads data from a buffer into locations given by a variable number of arguments.

int vswprintf(wchar_t *wcsbuffer, size_t n, const wchar_t *format, *va_list arg*);

Formats and stores a series of wide characters and values in the buffer wcsbuffer.

int vwprintf(const wchar_t *format, *va_list arg*);

Equivalent to wprintf, except that the variable argument list is replaced by arg.

int wctob(wint_t wc);

Determines whether wc corresponds to a member of the extended character set whose multibyte character representation is a single byte when in the initial shift state.

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stdio.h

Functions defined with #include <stdio.h>.

wint_t btowc(int c);

Determines whether c constitutes a valid multibyte character in the initial shift state.

void clearerr(FILE *stream);

Resets the error indicators and the end-of-file indicator for stream.

int fclose(FILE *stream);

Closes the specified stream.

FILE *fdopen(int handle, const char *type);

Associates an input or output stream with the file identified by handle.

int feof(FILE *stream);

Tests whether the end-of-file flag is set for a given stream.

int ferror(FILE *stream);

Tests for an error indicator in reading from or writing to stream.

int fflush(FILE *stream);

Writes the contents of the buffer associated with the output stream.

int fgetc(FILE *stream);

Reads a single unsigned character from the input stream.

int fgetpos(FILE *stream, fpos_t *pos);

Stores the current position of the file pointer associated with stream into the object pointed to by pos.

char *fgets(char *string, int n, FILE *stream);

Reads a string from the input stream.

wint_t fgetwc(FILE *stream);

Reads the next multibyte character from the input stream pointed to by stream.

wchar_t *fgetws(wchar_t *wcs, int n, FILE *stream);

Reads wide characters from the stream into the array pointed to by wcs.

int fileno(FILE *stream);

Determines the file handle currently associated with stream.

FILE *fopen(const char *filename, const char *mode);

Opens the specified file.

int fprintf(FILE *stream, const char **format-string*, *arg-list*);

Formats and prints characters and values to the output stream.

int fputc(int c, FILE *stream);

Prints a character to the output stream.

int fputs(const char *string, FILE *stream);

Copies a string to the output stream.

wint_t fputwc(wchar_t wc, FILE *stream);

Converts the wide character wc to a multibyte character and writes it to the output stream pointed to by stream at the current position.

int fputws(const wchar_t *wcs, FILE *stream);

Converts the wide-character string wcs to a multibyte-character string and writes it to stream as a multibyte character string.

size_t fread(void *buffer, size_t size, size_t count, FILE *stream);

Reads up to count items of size length from the input stream, and stores them in buffer.

FILE *freopen(const char *filename, const char *mode, FILE *stream);

Closes stream, and reassigns it to the file specified.

int fscanf(FILE *stream, const char **format-string*, *arg-list*);

Reads data from stream into locations given by arg-list.

int fseek(FILE *stream, long int offset, int origin);

Changes the current file position associated with stream to a new location.

int fsetpos(FILE *stream, const fpos_t *pos);

Moves the current file position to a new location determined by pos.

long int ftell(FILE *stream);

Gets the current position of the file pointer.

int fwide(FILE *stream, int mode);

Determines the orientation of the stream pointed to by stream.

int fwprintf(FILE *stream, const wchar_t *format, *arg-list*);

Writes output to the stream pointed to by stream.

size_t fwrite(const void *buffer, size_t size,size_t count, FILE *stream);

Writes up to count items of size length from buffer to stream.

int fwscanf(FILE *stream, const wchar_t *format, *arg-list*);

Reads input from the stream pointed to by stream.

int getc(FILE *stream);

Reads a single character from the input stream.

int getchar(void);

Reads a single character from stdin.

char *gets(char *buffer);

Reads a string from stdin, and stores it in buffer.

wint_t getwc(FILE *stream);

Reads the next multibyte character from stream, converts it to a wide character and advances the associated file position indicator for stream.

void perror(const char *string);

Prints an error message to stderr.

int printf(const char **format-string*, *arg-list*);

Formats and prints characters and values to stdout.

int putc(int c, FILE *stream);

Prints c to the output stream.

int putchar(int c);

Prints c to stdout.

int puts(const char *string);

Prints a string to stdout.

int remove(const char *filename);

Deletes the file specified by filename.

int rename(const char *oldname, const char *newname);

Renames the specified file.

void rewind(FILE *stream);

Repositions the file pointer associated with stream to the beginning of the file.

int scanf(const char **format-string*, *arg-list*);

Reads data from stdin into locations given by arg-list.

void setbuf(FILE *stream, char *buffer);

Controls buffering for stream.

int setvbuf(FILE *stream, char *buf, int type, size_t size);

Controls buffering and buffer size for stream.

int sprintf(char *buffer, const char **format-string*, *arg-list*);

Formats and stores characters and values in buffer.

int sscanf(const char *buffer, const char *format, *arg-list*);

Reads data from buffer into the locations given by arg-list.

FILE *tmpfile(void);

Creates a temporary binary file and opens it.

char *tmpnam(char *string);

Generates a temporary file name.

int ungetc(int c, FILE *stream);

Pushes c back onto the input stream.

wint_t ungetwc(wint_t wc, FILE *stream);

Pushes the wide character wc back onto the input stream.

int vfprintf(FILE *stream, const char *format, *va_list arg_ptr*);

Formats and prints characters to the output stream using a variable number of arguments.

int vfwprintf(FILE *stream, const wchar_t *format, *va_list arg*);

Equivalent to fwprintf, except that the variable argument list is replaced by arg.

int vfwscanf(FILE *stream, const wchar_t *format, *va_list arg_ptr*);

Reads wide data from a specified stream into locations given by a variable number of arguments.

int vscanf(const char *format, *va_list arg_ptr*);

Reads data from stdin into locations given by a variable number of arguments.

int vsscanf(const char*buffer, const char *format, *va_list arg_ptr*);

Reads data from a buffer into locations given by a variable number of arguments.

int vswscanf(const wchar_t *buffer, const wchar_t *format, *va_list arg_ptr*);

Reads wide data from a buffer into locations given by a variable number of arguments.

int vwscanf(const wchar_t *format, *va_list arg_ptr*);

Reads wide data from stdin into locations given by a variable number of arguments.

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stdlib.h

Functions defined with #include <stdlib.h>.

void abort(void);

Stops a program abnormally.

int abs(int n);

Calculates the absolute value of an integer argument n.

double atof(const char *string);

Converts string to a double-precision floating-point value.

int atoi(const char *string);

Converts string to an integer.

long int atol(const char *string);

Converts string to a long integer.

void *calloc(size_t num, size_t size);

Reserves storage space for an array of num elements, each of size size, and initializes the values of all elements to 0.

void exit(int status);

Ends a program normally.

void free(void *ptr);

Frees a block of storage.

char *getenv(const char *varname);

Searches environment variables for varname.

long int labs(long int n);

Calculates the absolute value of n.

void *malloc(size_t size);

Reserves a block of storage.

int mblen(const char *string, size_t n);

Determines the length of a multibyte character string.

size_t mbstowcs(wchar_t *pwc, const char *string, size_t n);

Converts the multibyte characters in string to their corresponding wchar_t codes, and stores not more than n codes in pwc.

int mbtowc(wchar_t *pwc, const char *string, size_t n);

Stores the wchar_t code corresponding to the first n bytes of multibyte character string into the wchar_t character pwc.

int *putenv(const char *varname);

Sets the value of an environment variable by altering an existing variable or creating a new one.

int rand(void);

Returns a pseudo-random integer.

int rand_r(void);

Returns a pseudo-random integer. (Restartable version)

void *realloc(void *ptr, size_t size);

Changes the size of a previously reserved storage block.

void srand(unsigned int seed);

Sets the seed for the pseudo-random number generator.

double strtod(const char *nptr, char **endptr);

Converts nptr to a double precision value.

float strtof(const char *nptr, char **endptr);

Converts nptr to a float value.

long int strtol(const char *nptr, char **endptr, int base);

Converts nptr to a signed long integer.

long double strtold(const char *nptr, char **endptr);

Converts nptr to a long double value.

unsigned long int strtoul(const char *string1, char **string2, int base);

Converts string1 to an unsigned long integer.

int system(const char *string);

Passes string to the system command analyzer.

size_t wcstombs(char *dest, const wchar_t *string, size_t count);

Converts the wchar_t string into a multibyte string dest.

int wctomb(char *string, wchar_t character);

Converts the wchar_t value of character into a multibyte string.

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string.h

Functions defined with #include <string.h>.

void *memchr(const void *buf, int c, size_t count);

Searches the first count bytes of buf for the first occurrence of c converted to an unsigned character.

int memcmp(const void *buf1, const void *buf2, size_t count);

Compares up to count bytes of buf1 and buf2.

void *memcpy(void *dest, const void *src, size_t count);

Copies count bytes of src to dest.

void *memmove(void *dest, const void *src, size_t count);

Copies count bytes of src to dest. Allows copying between objects that overlap.

void *memset(void *dest, int c, size_t count);

Sets count bytes of dest to a value c.

char *strcat(char *string1, const char *string2);

Concatenates string2 to string1.

char *strchr(const char *string, int c);

Locates the first occurrence of c in string.

int strcmp(const char *string1, const char *string2);

Compares the value of string1 to string2.

int strcoll(const char *string1, const char *string2);

Compares two strings using the collating sequence in the current locale.

char *strcpy(char *string1, const char *string2);

Copies string2 into string1.

size_t strcspn(const char *string1, const char *string2);

Returns the length of the initial substring of string1 consisting of characters not contained in string2.

char *strerror(int errnum);

Maps the error number in errnum to an error message string.

size_t strlen(const char *string);

Calculates the length of string.

char *strncat(char *string1, const char *string2, size_t count);

Concatenates up to count characters of string2 to string1.

int strncmp(const char *string1, const char *string2, size_t count);

Compares up to count characters of string1 and string2.

char *strncpy(char *string1, const char *string2, size_t count);

Copies up to count characters of string2 to string1.

char *strpbrk(const char *string1, const char *string2);

Locates the first occurrence in string1 of any character in string2.

char *strrchr(const char *string, int c);

Locates the last occurrence of c in string.

size_t strspn(const char *string1, const char *string2);

Returns the length of the initial substring of string1 consisting of characters contained in string2.

char *strstr(const char *string1, const char *string2);

Returns a pointer to the first occurrence of string2 in string1.

char *strtok(char *string1, const char *string2);

Locates the next token in string1 delimited by the next character in string2.

char *strtok_r(char *string, const char *seps, char **lasts);

Locates the next token in string delimited by the next character in seps. (Restartable version of strtok.)

size_t strxfrm(char *string1, const char *string2, size_t count);

Converts string2 and places the result in string1. The conversion is determined by the program's current locale.

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strings.h

Functions defined with #include <strings.h>.

int srtcasecmp(const char *string1, const char *string2);

Compares strings without case sensitivity.

int strncasecmp(const char *string1, const char *string2, size_t count);

Compares strings without case sensitivity.

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time.h

Functions defined with #include <time.h>.

char *asctime(const struct tm *time);

Converts the time that is stored as a structure to a character string.

char *asctime_r (const struct tm *tm, char *buf);

Converts tm that is stored as a structure to a character string. (Restartable version of asctime.)

char *ctime(const time_t *time);

Converts time to a character string.

char *ctime64(const time64_t *time);

Converts time to a character string.

char *ctime_r(const time_t *time, char *buf);

Converts time to a character string. (Restartable version of ctime.)

char *ctime64_r(const time64_t *time, char *buf);

Converts time to a character string. (Restartable version of ctime64.)

struct tm *gmtime(const time_t *time);

Converts a time value to a structure of type tm.

struct tm *gmtime64(const time64_t *time);

Converts a time value to a structure of type tm.

struct tm *gmtime_r (const time_t *time, struct tm *result);

Converts a time value to a structure of type tm. (Restartable version of gmtime.)

struct tm *gmtime64_r (const time64_t *time, struct tm *result);

Converts a time value to a structure of type tm. (Restartable version of gmtime64.)

struct tm *localtime(const time_t *timeval);

Converts timeval to a structure of type tm.

struct tm *localtime64(const time64_t *timeval);

Converts timeval to a structure of type tm.

struct tm *localtime_r (const time_t *timeval, struct tm *result);

Converts a time value to a structure of type tm. (Restartable version of localtime.)

struct tm *localtime64_r (const time64_t *timeval, struct tm *result);

Converts a time value to a structure of type tm. (Restartable version of localtime64.)

size_t strftime (char *dest, size_t maxsize, const char *format, const struct tm *timeptr);

Stores characters in an array pointed to by dest, according to the string determined by format.

char *strptime (const char *buf, const char *format, struct tm *tm);

Date and time conversion

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wchar.h

Functions defined with #include <wchar.h>.

wint_t btowc(int c);

Determines whether c constitutes a valid multibyte character in the initial shift state.

wint_t fgetwc(FILE *stream);

Reads the next multibyte character from the input stream pointed to by stream.

wchar_t *fgetws(wchar_t *wcs, int n, FILE *stream);

Reads wide characters from the stream into the array pointed to by wcs.

wint_t fputwc(wchar_t wc, FILE *stream);

Converts the wide character wc to a multibyte character and writes it to the output stream pointed to by stream at the current position.

int fputws(const wchar_t *wcs, FILE *stream);

Converts the wide-character string wcs to a multibyte-character string and writes it to stream as a multibyte character string.

int fwide(FILE *stream, int mode);

Determines the orientation of the stream pointed to by stream.

int fwprintf(FILE *stream, const wchar_t *format, *arg-list*);

Writes output to the stream pointed to by stream.

int fwscanf(FILE *stream, const wchar_t *format, *arg-list*);

Reads input from the stream pointed to by stream.

wint_t getwc(FILE *stream);

Reads the next multibyte character from stream, converts it to a wide character and advances the associated file position indicator for stream.

wint_t getwchar(void);

Reads the next multibyte character from stdin, converts it to a wide character, and advances the associated file position indicator for stdin.

int mbrlen (const char *s, size_t n, mbstate_t *ps);

Determines the length of a multibyte character. (Restartable version of mblen.)

int mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps);

Convert a multibyte character to a wide character (Restartable version of mbtowc.)

int mbsinit (const mbstate_t *ps);

Test state object ps for initial state.

size_t mbsrtowc (wchar_t *dst, const char **src, size_t len, mbstate_t *ps);

Convert multibyte string to a wide character string. (Restartable version of mbstowcs.)

wint_t putwchar(wchar_t wc);

Converts the wide character wc to a multibyte character and writes it to stdout.

int swprintf(wchar_t *wcsbuffer, size_t n, const wchar_t *format, *arg-list*);

Formats and stores a series of wide characters and values into the wide-character buffer wcsbuffer.

int swscanf (const wchar_t *buffer, const wchar_t *format, *arg-list*);

Reads data from buffer into the locations given by arg-list.

wint_t ungetwc(wint_t wc, FILE *stream);

Pushes the wide character wc back onto the input stream.

int vfwprintf(FILE *stream, const wchar_t *format, *va_list arg*);

Equivalent to fwprintf, except that the variable argument list is replaced by arg.

int vswprintf(wchar_t *wcsbuffer, size_t n, const wchar_t *format, *va_list arg*);

Formats and stores a series of wide characters and values in the buffer wcsbuffer.

int vswscanf(const wchar_t *buffer, const wchar_t *format, *va_list arg_ptr*);

Reads wide data from a buffer into locations given by a variable number of arguments.

int vwprintf(const wchar_t *format, *va_list arg*);

Equivalent to wprintf, except that the variable argument list is replaced by arg.

int vwscanf(const wchar_t *format, *va_list arg_ptr*);

Reads wide data from stdin into locations given by a variable number of arguments.

wchar_t *wcscat(wchar_t *string1, const wchar_t *string2);

Appends a copy of the string pointed to by string2 to the end of the string pointed to by string1.

wchar_t *wcschr(const wchar_t *string, wchar_t character);

Searches the wide-character string pointed to by string for the occurrence of character.

int wcscmp(const wchar_t *string1, const wchar_t *string2);

Compares two wide-character strings, string1 and string2.

int wcscoll (const wchar_t *wcs1, const wchar_t *wcs2);

Compares two wide-character strings using the collating sequence in the current locale.

wchar_t *wcscpy(wchar_t *string1, const wchar_t *string2);

Copies the contents of string2 (including the ending wchar_t null character) into string1.

size_t wcscspn(const wchar_t *string1, const wchar_t *string2);

Determines the number of wchar_t characters in the initial segment of the string pointed to by string1 that do not appear in the string pointed to by string2.

size_t wcsftime(wchar_t *wdest, size_t maxsize, const wchar_t *format, const struct tm *timeptr);

Converts the time and date specification in the timeptr structure into a wide-character string.

size_t wcslen(const wchar_t *string);

Computes the number of wide-characters in the string pointed to by string.

wchar_t *wcsncat(wchar_t *string1, const wchar_t *string2, size_t count);

Appends up to count wide characters from string2 to the end of string1, and appends a wchar_t null character to the result.

int wcsncmp(const wchar_t *string1, const wchar_t *string2, size_t count);

Compares up to count wide characters in string1 to string2.

wchar_t *wcsncpy(wchar_t *string1, const wchar_t *string2, size_t count);

Copies up to count wide characters from string2 to string1.

wchar_t *wcspbrk(const wchar_t *string1, const wchar_t *string2);

Locates the first occurrence in the string pointed to by string1 of any wide characters from the string pointed to by string2.

wchar_t *wcsptime ( const wchar_t *buf, const wchar_t *format, struct tm *tm );

Date and time conversion. Equivalent to strptime(), except that it uses wide characters.

wchar_t *wcsrchr(const wchar_t *string, wchar_t character);

Locates the last occurrence of character in the string pointed to by string.

size_t wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps);

Converts wide character string to multibyte string. (Restartable version of wcstombs.)

size_t wcsspn(const wchar_t *string1, const wchar_t *string2);

Computes the number of wide characters in the initial segment of the string pointed to by string1, which consists entirely of wide characters from the string pointed to by string2.

wchar_t *wcsstr(const wchar_t *wcs1, const wchar_t *wcs2);

Locates the first occurrence of wcs2 in wcs1.

double wcstod(const wchar_t *nptr, wchar_t **endptr);

Converts the initial portion of the wide-character string pointed to by nptr to a double value.

float wcstof(const wchar_t *nptr, wchar_t **endptr);

Converts the initial portion of the wide-character string pointed to by nptr to a float value.

wchar_t *wcstok(wchar_t *wcs1, const wchar_t *wcs2, wchar_t **ptr);

Breaks wcs1 into a sequence of tokens, each of which is delimited by a wide character from the wide string pointed to by wcs2.

long int wcstol(const wchar_t *nptr, wchar_t **endptr, int base);

Converts the initial portion of the wide-character string pointed to by nptr to a long integer value.

long double wcstold(const wchar_t *nptr, wchar_t **endptr);

Converts the initial portion of the wide-character string pointed to by nptr to a long double value.

unsigned long int wcstoul(const wchar_t *nptr, wchar_t **endptr, int base);

Converts the initial portion of the wide-character string pointed to by nptr to an unsigned long integer value.

size_t wcsxfrm (wchar_t *wcs1, const wchar_t *wcs2, size_t n);

Transforms a wide-character string to values which represent character collating weights and places the resulting wide-character string into an array.

int wctob(wint_t wc);

Determines whether wc corresponds to a member of the extended character set whose multibyte character representation is a single byte when in the initial shift state.

int wcswidth(const wchar_t *pwcs, size_t n);

Determine the display width of a wide character string.

wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n);

Locates the first occurrence of c in the initial n wide characters of the object pointed to by s.

int wmemcmp(const wchar_t *s1, const wchar_t *s2, size_t n);

Compares the first n wide characters of the object pointed to by s1 to the first n characters of the object pointed to by s2.

wchar_t *wmemcpy(wchar_t *s1, const wchar_t *s2, size_t n);

Copies n wide characters from the object pointed to by s2 to the object pointed to by s1.

wchar_t *wmemmove(wchar_t *s1, const wchar_t *s2, size_t n);

Copies n wide characters from the object pointed to by s2 to the object pointed to by s1.

wchar_t *wmemset(wchar_t *s, wchar_t c, size_t n);

Copies the value of c into each of the first n wide characters of the object pointed to by s.

int wprintf(const wchar_t *format, *arg-list*);

Equivalent to fwprintf with the argument stdout interposed before the arguments to wprintf.

int wscanf(const wchar_t *format, *arg-list*);

Equivalent to fwscanf with the argument stdin interposed before the arguments of wscanf.

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wctype.h

Functions defined with #include <wctype.h>.

int iswalnum (wint_t wc);

Checks for any alphanumeric wide character.

int iswalpha (wint_t wc);

Checks for any alphabetic wide character.

int iswblank (wint_t wc);

Checks for any blank or tab wide character.

int iswcntrl (wint_t wc);

Tests for any control wide character.

int iswdigit (wint_t wc);

Checks for any decimal-digit wide character.

int iswgraph (wint_t wc);

Checks for any printing wide character except for the wide-character space.

int iswlower (wint_t wc);

Checks for any lowercase wide character.

int iswprint (wint_t wc);

Checks for any printing wide character.

int iswpunct (wint_t wc);

Test for a wide non-alphanumeric, non-space character.

int iswspace (wint_t wc);

Checks for any wide character that corresponds to an implementation-defined set of wide characters for which iswalnum is false.

int iswupper (wint_t wc);

Checks for any uppercase wide character.

int iswxdigit (wint_t wc);

Checks for any hexadecimal digit character.

int isxdigit(int c);

Tests if c is a hexadecimal digit.

wint_t towlower (wint_t wc);

Converts uppercase letter to lowercase letter.

wint_t towupper (wint_t wc);

Converts lowercase letter to uppercase letter.