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Get a string from the terminal screen, store it in the variable str, and echo it on the specified window. The getstr function works on the stdscr window.
#include <curses.h>int getstr (char *str);
int wgetstr (WINDOW *win, char *str);
win
A pointer to the window.str
Must be large enough to hold the character string fetched from the window.
The getstr and wgetstr functions refresh the specified window before fetching a string. The new-line terminator is stripped from the fetched string. For more information, see the scrollok function in this section.
OK Indicates success. ERR Indicates that the function makes the screen scroll illegally.
Gets date and time.
#include <time.h>int gettimeofday (struct timeval *tp, void *tpz);
tp
Pointer to a timeval structure, defined in the <time.h> header file.tpz
A NULL pointer. If this argument is not a NULL pointer, it is ignored.
This function gets the current time (expressed as seconds and microseconds) since 00::00 Coordinated Universal Time, January 1, 1970. The current time is stored in the timeval structure pointed to by the tp argument.The tzp argument is intended to hold time-zone information set by the kernel. However, because the OpenVMS kernel does not set time-zone information, the tzp argument should be NULL. If it is not NULL, it is ignored. This function is supported for compatibility with BSD programs.
If the value of the SYS$TIMEZONE_DIFFERENTIAL logical is wrong, the function fails with errno set to EINVAL.
0 Indicates success. --1 An error occurred. errno is set to indicate the error.
Returns, in OpenVMS terms, the member number from the user identification code (UIC). For example, if the UIC is [313,031], 031 is the member number.
#include <unistd.h>uid_t getuid (void);
In Compaq C for OpenVMS Systems, getuid and geteuid perform the same function.For programs compiled with the _VMS_V6_SOURCE feature-test macro or programs that do not include the <unistd.h> header file, the getuid and geteuid functions return the member number of the OpenVMS UIC. For example, if the UIC is [313,31], then the member number, 31, is returned.
For programs compiled without the _VMS_V6_SOURCE feature-test macro that do include the <unistd.h> header file, the full UIC is returned. For example, if the UIC is [313, 31] then 20512799 (31 + 313 * 65536) is returned.
Note (ALPHA ONLY)
On OpenVMS Alpha systems, this function has been enhanced to take advantage of the new OpenVMS support for POSIX-style user, group, and session IDs available on a version of OpenVMS Alpha after Version 7.3.
The new functionality, based on PERSONA VMS services, is the default on those versions of OpenVMS Alpha where the underlying operating system support is available.
To request the old behavior, define the DECC$GETJPI_BASED_UID logical name to "ENABLE":
$ DEFINE DECC$GETJPI_BASED_UID ENABLE
x The member number from the current UIC, or the full UIC. See description.
Returns characters from a specified file.
#include <stdio.h>int getw (FILE *file_ptr);
file_ptr
A pointer to the file to be accessed.
This function returns the next four characters from the specified input file as an int .
x The next four characters, in an int . EOF Indicates that the end-of-file was encountered during the retrieval of any of the four characters and all four characters were lost. Since EOF is an acceptable integer, use feof and ferror to check the success of the function.
Reads the next character from a specified file, and converts it to a wide-character code.
#include <wchar.h>wint_t getwc (FILE *file_ptr);
file_ptr
A pointer to the file to be accessed.
Since getwc is implemented as a macro, a file pointer argument with side effects (for example getwc (*f++) ) might be evaluated incorrectly. In such a case, use the fgetwc function instead. See the fgetwc function in this section.
n The returned character. WEOF Indicates the end-of-file or an error. If an error occurs, the function sets errno . For a list of the values set by this function, see fgetwc in this section.
Reads a single wide character from the standard input (stdin).
#include <wchar.h>wint_t getwchar (void);
The getwchar function is identical to fgetwc(stdin) .
x The next character from stdin, converted to wint_t . WEOF Indicates the end-of-file or an error. If an error occurs, the function sets errno . For a list of the values set by this function, see fgetwc in this section.
Puts the (y,x) coordinates of the current cursor position on win in the variables y and x.
#include <curses.h>getyx (WINDOW *win, int y, int x);
win
Must be a pointer to the window.y
Must be a valid lvalue.x
Must be a valid lvalue.
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 this 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 Compaq 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 process-wide 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 one of the following values:
- 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 this 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 also raise , signal , ssignal , and sigvec in this section.
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 square root of the sum of the squares of two arguments:
sqrt(x2 + y2)
#include <math.h>double hypot (double x, double y);
x
A real value.y
A real value.
On overflow, the return value is undefined.
Converts characters coded in one codeset to characters coded in another codeset.
#include <iconv.h>size_t iconv (iconv_t cd, 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.
This 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 non-identical 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 -- Non-translatable VMS 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 VMS error occur. vaxc$errno contains the VMS error code. A value of SS$_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); }
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