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Frees any space associated with the pglob argument resulting from a previous call to the glob function.
#include <glob.h>Function Variants The globfree function has variants named _globfree32 and _globfree64 for use with 32-bit and 64-bit pointer sizes, respectively. See Section 1.10 for more information on using pointer-size-specific functions.void globfree (glob_t *pglob);
pglob
Pointer to a previously allocated glob_t structure.
The globfree function frees any space associated with the pglob argument resulting from a previous call to the glob function. The globfree function returns no value.
Converts time units to the broken-down UTC time.
#include <time.h>Function Variants Compiling with the _DECC_V4_SOURCE and _VMS_V6_SOURCE feature-test macros defined enables a local-time-based entry point to the gmtime_r function that is equivalent to the behavior before OpenVMS Version 7.0.struct tm *gmtime (const time_t *timer);
struct tm *gmtime_r (const time_t *timer, struct tm *result); (ISO POSIX-1)
timer
Points to a variable that specifies a time value in seconds since the Epoch.result
A pointer to a tm structure where the result is stored.The tm structure is defined in the <time.h> header, and is also shown in Table REF-4 in the description of localtime .
The gmtime and gmtime_r functions convert the time (in seconds since the Epoch) pointed to by timer into a broken-down time, expressed as Coordinated Universal Time (UTC), and store it in a tm structure.The difference between the gmtime_r and gmtime functions is that the former puts the result into a user-specified tm structure where the result is stored. The latter puts the result into thread-specific static memory allocated by the HP C RTL, and which is overwritten by subsequent calls to gmtime ; you must make a copy if you want to save it.
On success, gmtime returns a pointer to the tm structure; gmtime_r returns its second argument. On failure, these functions return the NULL pointer.
Note
Generally speaking, UTC-based time functions can affect in-memory time-zone information, which is processwide data. However, if the system time zone remains the same during the execution of the application (which is the common case) and the cache of timezone files is enabled (which is the default), then the _r variant of the time functions asctime_r , ctime_r , gmtime_r and localtime_r , is both thread-safe and AST-reentrant.
If, however, the system time zone can change during the execution of the application or the cache of timezone files is not enabled, then both variants of the UTC-based time functions belong to the third class of functions, which are neither thread-safe nor AST-reentrant.
x Pointer to a tm structure. NULL Indicates an error; errno is set to the following value:
- EINVAL -- The timer argument is NULL.
Generates a specified software signal, which invokes the action routine established by a signal , ssignal , or sigvec function.
#include <signal.h>int gsignal (int sig [, int sigcode]);
sig
The signal to be generated.sigcode
An optional signal code. For example, signal SIGFPE---the arithmetic trap signal---has 10 different codes, each representing a different type of arithmetic trap.The signal codes can be represented by mnemonics or numbers. The arithmetic trap codes are represented by the numbers 1 to 10, but the SIGILL codes are represented by the numbers 0 to 2. The code values are defined in the <signal.h> header file. See Tables 4-4 and 4-5 for a list of signal mnemonics, codes, and corresponding OpenVMS exceptions.
Calling the gsignal function has one of the following results:
- If gsignal specifies a sig argument that is outside the range defined in the <signal.h> header file, then gsignal returns 0 and sets errno to EINVAL.
- If signal , ssignal , or sigvec establishes SIG_DFL (default action) for the signal, then gsignal does not return. The image is exited with the OpenVMS error code corresponding to the signal.
- If signal , ssignal , or sigvec establishes SIG_IGN (ignore signal) as the action for the signal, then gsignal returns its argument, sig.
- signal , ssignal , or sigvec must be used to establish an action routine for the signal. That function is called and its return value is returned by gsignal .
See Chapter 4 for more information.
0 Indicates a sig argument that is outside the range defined in the <signal.h> header file; errno is set to EINVAL. sig Indicates that SIG_IGN (ignore signal) has been established as the action for the signal. x Indicates that signal , ssignal , or sigvec has established an action function for the signal. That function is called, and its return value is returned by gsignal .
Returns the length of the hypotenuse of a right triangle.
#include <math.h>double hypot (double x, double y);
float hypotf (float x, float y); (ALPHA, I64)
long double hypotl (long double x, long double y); (ALPHA, I64)
x
A real value.y
A real value.
The hypot functions return the length of the hypotenuse of a right triangle, where x and y represent the perpendicular sides of the triangle. The length is calculated as:
sqrt(x2 + y2)
On overflow, the return value is undefined, and errno is set to ERANGE.
x The length of the hypotenuse. HUGE_VAL Overflow occurred; errno is set to ERANGE. 0 Underflow occurred; errno is set to ERANGE. NaN x or y is NaN; errno is set to EDOM.
Converts characters coded in one codeset to characters coded in another codeset.
#include <iconv.h>size_t iconv (iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
cd
A conversion descriptor. This is returned by a successful call to iconv_open .inbuf
A pointer to a variable that points to the first character in the input buffer.inbytesleft
Initially, this argument is a pointer to a variable that indicates the number of bytes to the end of the input buffer (inbuf). When the conversion is completed, the variable indicates the number of bytes in inbuf not converted.outbuf
A pointer to a variable that points to the first available byte in the output buffer. The output buffer contains the converted characters.outbytesleft
Initially, this argument is a pointer to a variable that indicates the number of bytes to the end of the output buffer (outbuf). When the conversion is completed, the variable indicates the number of bytes left in outbuf.
The iconv function converts characters in the buffer pointed to by inbuf to characters in another code set. The resulting characters are stored in the buffer pointed to by outbuf. The conversion type is specified by the conversion descriptor cd. This descriptor is returned from a successful call to iconv_open .If an invalid character is found in the input buffer, the conversion stops after the last successful conversion. The variable pointed to by inbytesleft is updated to reflect the number of bytes in the input buffer that are not converted. The variable pointed to by outbytesleft is updated to reflect the number of bytes remaining in the output buffer.
x Number of nonidentical conversions performed. Indicates successful conversion. In most cases, 0 is returned. ( size_t ) - 1 Indicates an error condition. The function sets errno to one of the following:
- EBADF -- The cd argument is not a valid conversion descriptor.
- EILSEQ -- The conversion stops when an invalid character detected.
- E2BIG -- The conversion stops because of insufficient space in the output buffer.
- EINVAL -- The conversion stops because of an incomplete character at the end of the input buffer.
Deallocates a specified conversion descriptor and the resources allocated to the descriptor.
#include <iconv.h>int iconv_close (iconv_t cd);
cd
The conversion descriptor to be deallocated. A conversion descriptor is returned by a successful call to iconv_open .
0 Indicates that the conversion descriptor was successfully deallocated. - 1 Indicates an error occurred. The function sets errno to one of the following:
- EBADF -- The cd argument is not a valid conversion descriptor.
- EVMSERR -- Nontranslatable OpenVMS error occur. vaxc$errno contains the VMS error code.
Allocates a conversion descriptor for a specified codeset conversion.
#include <iconv.h>iconv_t iconv_open (const char *tocode, const char *fromcode);
tocode
The name of the codeset to which characters are converted.fromcode
The name of the source codeset. See Chapter 10 for information on obtaining a list of currently available codesets or for details on adding new codesets.
x A conversion descriptor. Indicates the call was successful. This descriptor is used in subsequent calls to iconv (iconv_t) - 1 Indicates an error occurred. The function sets errno to one of the following:
- EMFILE -- The process does not have enough I/O channels to open a file.
- ENOMEM -- Insufficient space is available.
- EINVAL -- The conversion specified by fromcode and tocode is not supported.
- EVMSERR -- Nontranslatable OpenVMS error occur. vaxc$errno contains the OpenVMS error code. A value of SS$_BADCHKSUM in vaxc$errno indicates that a conversion table file was found, but its contents is corrupted. A value of SS$_IDMISMATCH in vaxc$errno indicates that the conversion table file version does not match the version of the C Run-Time Library.
#include <stdio.h> #include <iconv.h> #include <errno.h> int main() { /* Declare variables to be used */ char fromcodeset[30]; char tocodeset[30]; int iconv_opened; iconv_t iconv_struct; /* Iconv descriptor */ /* Initialize variables */ sprintf(fromcodeset, "DECHANYU"); sprintf(tocodeset, "EUCTW"); iconv_opened = FALSE; /* Attempt to create a conversion descriptor for the */ /* codesets specified. If the return value from */ /* iconv_open is -1 then an error has occurred. */ /* Check the value of errno. */ if ((iconv_struct = iconv_open(tocodeset, fromcodeset)) == (iconv_t) - 1) { /* Check the value of errno */ switch (errno) { case EMFILE: case ENFILE: printf("Too many iconv conversion files open\n"); break; case ENOMEM: printf("Not enough memory\n"); break; case EINVAL: printf("Unsupported conversion\n"); break; default: printf("Unexpected error from iconv_open\n"); break; } } else /* Successfully allocated a conversion descriptor */ iconv_opened = TRUE; /* Was a conversion descriptor allocated */ if (iconv_opened) { /* Attempt to deallocate the conversion descriptor. */ /* If iconv_close returns -1 then an error has */ /* occurred. */ if (iconv_close(iconv_struct) == -1) { /* An error occurred. Check the value of errno */ switch (errno) { case EBADF: printf("Conversion descriptor is invalid\n"); break; default: printf("Unexpected error from iconv_close\n"); break; } } } return (EXIT_FAILURE); }
Returns the exponent part of its argument.
#include <math.h>int ilogb (double x);
int ilogbf (float x);
int ilogbl (long double x);
x
A real value.
The ilogb functions return the exponent part of their argument x. Formally, the return value is the integral part of logr|x| as a signed integral value, for non-zero x, where r is the radix of the machine's floating-point arithmetic, which is the value of FLT_RADIX defined in <float.h> .
n Upon success, the exponent part of x as a signed integer value. These functions are equivalent to calling the corresponding logb function and casting the returned value to type int .
Return the character at the current cursor position on the specified window without making changes to the window. The inch function acts on the stdscr window.
#include <curses.h>char inch();
char winch (WINDOW *win);
win
A pointer to the window.
x The returned character. ERR Indicates an input error.
Searches for a character in a string.
#include <strings.h>Function Variants The index function has variants named _index32 and _index64 for use with 32-bit and 64-bit pointer sizes, respectively. See Section 1.10 for more information on using pointer-size-specific functions.char *index (const char *s, int c);
s
The string to search.c
The character to search for.
The index function is identical to the strchr function, and is provided for compatibility with some UNIX implementations.
Initializes the terminal-type data and all screen functions. You must call initscr before using any of the curses functions.
#include <curses.h>void initscr (void);
The OpenVMS Curses version of the initscr function clears the screen before doing the initialization. The BSD-based Curses version does not.
Initializes random-number generators.
#include <stdlib.h>char *initstate (unsigned int seed, char *state, int size);
seed
An initial seed value.state
Pointer to an array of state information.size
The size of the state information array.
The initstate function initializes random-number generators. It lets you initialize, for future use, a state array passed as an argument. The size, in bytes, of the state array is used by the initstate function to decide how sophisticated a random-number generator to use; the larger the state array, the more random the numbers.Values for the amount of state information are 8, 32, 64, 128, and 256 bytes. Amounts less than 8 bytes generate an error, while other amounts are rounded down to the nearest known value.
The seed argument specifies a starting point for the random-number sequence and provides for restarting at the same point. The initstate function returns a pointer to the previous state information array.
Once you initialize a state, the setstate function allows rapid switching between states. The array defined by the state argument is used for further random-number generation until the initstate function is called or the setstate function is called again. The setstate function returns a pointer to the previous state array.
After initialization, you can restart a state array at a different point in one of two ways:
- Use the initstate function with the desired seed argument, state array, and size of the array.
- Use the setstate function with the desired state, followed by the srandom function with the desired seed. The advantage of using both functions is that you do not have to save the state array size once you initialize it.
See also setstate , srandom , and random .
x A pointer to the previous state array information. 0 Indicates an error. Call made with less than 8 bytes of state information. Further specified in the global errno .
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