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Compaq C

Compaq C
Run-Time Library Reference Manual for OpenVMS Systems


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strdup

Finds and points to a duplicate string.

Format

#include <string.h>

char *strdup (const char *s1);

Function Variants This function also has variants named _strdup32 and _strdup64 for use with 32-bit and 64-bit pointer sizes, respectively. See Section 1.10 for more information on using pointer-size-specific functions.

Arguments

s1

The first of two strings to compare.

Description

This function returns a pointer to a string that is an exact duplicate of the string pointed to by s1. The malloc function is used to allocate space for the new string. The strdup function is provided for compatibility with existing systems.

Return Values

x A pointer to the resulting string.
NULL Indicates an error.

strerror

Maps the error number in error_code to a locale-dependent error message string.

Format

#include <string.h>

char *strerror (int error_code); (ANSI C)

char *strerror (int error_code[, int vms_error_code]); (COMPAQ C EXTENSION)


Arguments

error_code

An error code.

vms_error_code

An OpenVMS error code.

Description

This function uses the error number in error_code to retrieve the appropriate locale-dependent error message. The contents of the error message strings are determined by the LC_MESSAGES category of the program's current locale.

When a program is not compiled with any standards-related feature-test macros (see Section 1.5.1), strerror has a second argument (vms_error_code), which is used in the following way:

  • If error_code is EVMSERR and there is a second argument, then that second argument is used as the vaxc$errno value.
  • If error_code is EVMSERR and there is no second argument, look at vaxc$errno to get the OpenVMS error condition.

See the strerror example.

Use of the second argument is not included in the ANSI C definition of strerror and is, therefore, not portable.

Because no return value is reserved to indicate an error, applications should set the value of errno to 0, call strerror , and then test the value of errno ; a nonzero value indicates an error condition.


Return Values

x A pointer to a buffer containing the appropriate error message. Do not modify this buffer in your programs. Moreover, calls to the strerror function may overwrite this buffer with a new message.

Example


#include <stdio.h> 
#include <errno.h> 
#include <string.h> 
#include <stdlib.h> 
#include <ssdef.h> 
 
main() 
{ 
    puts(strerror(EVMSERR)); 
    errno = EVMSERR; 
    vaxc$errno = SS$_LINKEXIT; 
    puts(strerror(errno)); 
    puts(strerror(EVMSERR, SS$_ABORT)); 
    exit(1); 
} 

Running this example produces the following output:


non-translatable vms error code: <none> 
network partner exited 
abort 


strfmon

Converts a number of monetary values into a string. The conversion is controlled by a format string.

Format

#include <monetary.h>

ssize_t strfmon (char *s, size_t maxsize, const char *format, ...);


Arguments

s

A pointer to the resultant string.

maxsize

The maximum number of bytes to be stored in the resultant string.

format

A pointer to a string that controls the format of the output string.

...

The monetary values of type double that are to be formatted for the output string. There should be as many values as there are conversion specifications in the format string pointed to by format. The function fails if there are insufficient values. Excess arguments are ignored.

Description

This function creates a string pointed to by s, using the monetary values supplied. A maximum of maxsize bytes is copied to s.

The format string pointed to by format consists of ordinary characters and conversion specifications. All ordinary characters are copied unchanged to the output string. A conversion specification defines how one of the monetary values supplied is formatted in the output string.

A conversion specification consists of a percent character (%), followed by a number of optional characters (see Table REF-5), and concluding with a conversion specifier (see Table REF-6).

If any of the optional characters listed in Table REF-5 is included in a conversion specification, they must appear in the order shown.

Table REF-5 Optional Characters in strfmon Conversion Specifications
Character Meaning
= character Use character as the numeric fill character if a left precision is specified. The default numeric fill character is the space character. The fill character must be representable as a single byte in order to work with precision and width count. This conversion specifier is ignored unless a left precision is specified, and it does not affect width filling, which always uses the space character.
^ Do not use separator characters to format the number. By default, the digits are grouped according to the mon_grouping field in the LC_MONETARY category of the current locale.
+ Add the string specified by the positive_sign or negative_sign fields in the current locale. If p_sign_posn or n_sign_posn is set to zero, then parentheses are used by default to indicate negative values. Otherwise, sign strings are used to indicate the sign of the value. You cannot use a + and a ( in the same conversion specification.
( Enclose negative values within parentheses. The default is taken from the p_sign_posn and n_sign_posn fields in the current locale. If p_sign_posn or n_sign_posn is set to zero, then parentheses are used by default to indicate negative values. Otherwise, sign strings are used to indicate the sign of the value. You cannot use a + and ( in the same conversion specification.
! Suppress the currency symbol. By default, the currency symbol is included.
-- Left-justify the value within the field. By default, values are right-justified.
field width A decimal integer that specifies the minimum field width in which to align the result of the conversion. The default field width is the smallest field that can contain the result.
#left_precision A # followed by a decimal integer specifies the number of digits to the left of the radix character. Extra positions are filled by the fill character. By default the precision is the smallest required for the argument. If grouping is not suppressed with the ^ conversion specifier, and if grouping is defined for the current locale, grouping separators are inserted before any fill characters are added. Grouping separators are not applied to fill characters even if the fill character is defined as a digit.
.right_precision A period (.) followed by a decimal integer specifies the number of digits to the right of the radix character. Extra positions are filled with zeros. The amount is rounded to this number of decimal places. If the right precision is zero, the radix character is not included in the output. By default the right precision is defined by the frac_digits or int_frac_digits field of the current locale.

Table REF-6 strfmon Conversion Specifiers
Specifier Meaning
i Use the international currency symbol defined by the int_currency_symbol field in the current locale, unless the currency symbol has been suppressed.
n Use the local currency symbol defined by the currency_symbol field in the current locale, unless the currency symbol has been suppressed.
% Output a % character. The conversion specification must be %%; none of the optional characters is valid with this specifier.


Return Values

x The number of bytes written to the string pointed to by s, not including the null terminating character.
--1 Indicates an error.The function sets errno to one of the following values:
  • EINVAL -- A conversion specification is syntactically incorrect.
  • E2BIG -- Processing the complete format string would produce more than maxsize bytes.

Example


#include <stdlib.h> 
#include <stdio.h> 
#include <locale.h> 
#include <monetary.h> 
#include <errno.h> 
 
#define MAX_BUF_SIZE 124 
 
main() 
{ 
  size_t ret; 
  char buffer[MAX_BUF_SIZE]; 
  double amount = 102593421; 
 
 /* Display a monetary amount using the en_US.ISO8859-1 */ 
 /* locale and a range of different display formats.    */ 
 
  if (setlocale(LC_ALL, "en_US.ISO8859-1") == (char *) NULL) { 
      perror("setlocale"); 
      exit(EXIT_FAILURE); 
  } 
  ret = strfmon(buffer, MAX_BUF_SIZE, "International: %i\n", amount); 
  printf(buffer); 
 
  ret = strfmon(buffer, MAX_BUF_SIZE, "National:      %n\n", amount); 
  printf(buffer); 
 
  ret = strfmon(buffer, MAX_BUF_SIZE, "National:      %=*#10n\n", amount); 
  printf(buffer); 
 
  ret = strfmon(buffer, MAX_BUF_SIZE, "National:     %(n\n", -1 * amount); 
  printf(buffer); 
 
  ret = strfmon(buffer, MAX_BUF_SIZE, "National:      %^!n\n", amount); 
  printf(buffer); 
} 

Running the example program produces the following result:


International: USD 102,593,421.00 
National:      $102,593,421.00 
National:      $**102,593,421.00 
National:      ($102,593,421.00) 
National:      102593421.00 


strftime

Uses date and time information stored in a tm structure, to create an output string. The format of the output string is controlled by a format string.

Format

#include <time.h>

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

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.

Arguments

s

A pointer to the resultant string.

maxsize

The maximum number of bytes to be stored in the resultant string, including the null terminator.

format

A pointer to a string that controls the format of the output string.

timeptr

A pointer to the local time ( tm ) structure. The tm structure is defined in the <time.h> header file.

Description

This function uses data in the structure pointed to by timeptr to create the string pointed to by s. A maximum of maxsize bytes is copied to s.

The format string consists of zero or more conversion specifications and ordinary characters. All ordinary characters (including the terminating null character) are copied unchanged into the output string. A conversion specification defines how data in the tm structure is formatted in the output string.

A conversion specification consists of a percent (%) character followed by one or more optional characters (see Table REF-7), and concluding with a conversion specifier (see Table REF-8). If any of the optional characters listed in Table REF-7 are specified, they must appear in the order shown in the table.

The strftime function behaves as if it called tzset .

Table REF-7 Optional Elements of strftime Conversion Specifications
Element Meaning
-- Optional with the field width to specify that the field is left-justified and padded with spaces. This cannot be used with the 0 element.
0 Optional with the field width to specify that the field is right-justified and padded with zeros. This cannot be used with the -- element.
field width A decimal integer that specifies the maximum field width
.precision A decimal integer that specifies the precision of data in a field.

For the d, H, I, j, m, M, o, S, U, w, W, y and Y conversion specifiers, the precision specifier is the minimum number of digits to appear in the field. If the conversion specification has fewer digits than that specified by the precision, leading zeros are added.

For the a, A, b, B, c, D, E, h, n, N, p, r, t, T, x, X, Z, and % conversion specifiers, the precision specifier is the maximum number of characters to appear in the field. If the conversion specification has more characters than that specified by the the precision, characters are truncated on the right.

The default precision for the d, H, I, m, M, o, S, U, w, W, y and Y conversion specifiers is 2; the default precision for the j conversion specifier is 3.

Note that the list of conversion specifications in Table REF-7 are extensions to the XPG4 specification.

Table REF-8 lists the conversion specifiers. The strftime function uses fields in the LC_TIME category of the program's current locale to provide a value. For example, if %B is specified, the function accesses the mon field in LC_TIME to find the full month name for the month specified in the tm structure. The result of using invalid conversion specifiers is undefined.

Table REF-8 strftime Conversion Specifiers
Specifier Replaced by
a The locale's abbreviated weekday name
A The locale's full weekday name
b The locale's abbreviated month name
B The locale's full month name
c The locale's appropriate date and time representation
C The century number (the year divided by 100 and truncated to an integer) as a decimal number (00 -- 99)
d The day of the month as a decimal number (01 -- 31)
D Same as %m/%d/%y
e The day of the month as a decimal number (1 -- 31) in a 2 digit field with the leading space character fill
Ec The locale's alternative date and time representation
EC The name of the base year (period) in the locale's alternative representation
Ex The locale's alternative date representation
EX The locale's alternative time representation
Ey The offset from the base year (%EC) in the locale's alternative representation
EY The locale's full alternative year representation
h Same as %b
H The hour (24-hour clock) as a decimal number (00 -- 23)
I The hour (12-hour clock) as a decimal number (01 -- 12)
j The day of the year as a decimal number (001 -- 366)
m The month as a decimal number (01 -- 12)
M The minute as a decimal number (00 -- 59)
n The newline character
Od The day of the month using the locale's alternative numeric symbols
Oe The date of the month using the locale's alternative numeric symbols
OH The hour (24-hour clock) using the locale's alternative numeric symbols
OI The hour (12-hour clock) using the locale's alternative numeric symbols
Om The month using the locale's alternative numeric symbols
OM The minutes using the locale's alternative numeric symbols
OS The seconds using the locale's alternative numeric symbols
Ou The weekday as a number in the locale's alternative representation (Monday=1)
OU The week number of the year (Sunday as the first day of the week) using the locale's alternative numeric symbols
OV The week number of the year (Monday as the first day of the week) as a decimal number (01 --53) using the locale's alterntative numeric symbols. If the week containing January 1 has four or more days in the new year, it is considered as week 1. Otherwise, it is considered as week 53 of the previous year, and the next week is week 1.
Ow The weekday as a number (Sunday=0) using the locale's alternative numeric symbols
OW The week number of the year (Monday as the first day of the week) using the locale's alternative numeric symbols
Oy The year without the century using the locale's alternative numeric symbols
p The locale's equivalent of the AM/PM designations associated with a 12-hour clock
r The time in AM/PM notation
R The time in 24-hour notation (%H:%M)
S The second as a decimal number (00 -- 61)
t The tab character
T The time (%H:%M:%S)
u The weekday as a decimal number between 1 and 7 (Monday=1)
U The week number of the year (the first Sunday as the first day of week 1) as a decimal number (00 -- 53)
V The week number of the year (Monday as the first day of the week) as a decimal number (00 -- 53). If the week containing January 1 has four or more days in the new year, it is considered as week 1. Otherwise, it is considered as week 53 of the previous year, and the next week is week 1.
w The weekday as a decimal number (0 [Sunday] -- 6)
W The week number of the year (the first Monday as the first day of week 1) as a decimal number (00 -- 53)
x The locale's appropriate date representation
X The locale's appropriate time representation
y The year without century as a decimal number (00 -- 99)
Y The year with century as a decimal number
Z Time-zone name or abbreviation. If time-zone information is not available, no character is output.
% %


Return Values

x The number of characters placed into the array pointed to by s, not including the terminating null character.
0 Indicates an error occurred. The contents of the array are indeterminate.

Example


#include <stdlib.h> 
#include <stdio.h> 
#include <time.h> 
#include <locale.h> 
#include <errno.h> 
 
#define NUM_OF_DATES  7 
#define BUF_SIZE 256 
 
/* This program formats a number of different dates, once */ 
/* using the C locale and then using the fr_FR.ISO8859-1  */ 
/* locale. Date and time formatting is done using strftime(). */ 
 
main() 
{ 
    int count, 
        i; 
    char buffer[BUF_SIZE]; 
    struct tm *tm_ptr; 
    time_t time_list[NUM_OF_DATES] = 
    {500, 68200000, 694223999, 694224000, 
     704900000, 705000000, 705900000}; 
 
    /* Display dates using the C locale */ 
    printf("\nUsing the C locale:\n\n"); 
 
    setlocale(LC_ALL, "C"); 
 
    for (i = 0; i < NUM_OF_DATES; i++) { 
        /* Convert to a tm structure */ 
        tm_ptr = localtime(&time_list[i]); 
 
        /* Format the date and time */ 
        count = strftime(buffer, BUF_SIZE, 
               "Date: %A %d %B %Y%nTime: %T%n%n", tm_ptr); 
        if (count == 0) { 
            perror("strftime"); 
            exit(EXIT_FAILURE); 
        } 
 
        /* Print the result */ 
       printf(buffer); 
    } 
 
    /* Display dates using the fr_FR.ISO8859-1 locale */ 
    printf("\nUsing the fr_FR.ISO8859-1 locale:\n\n"); 
 
    setlocale(LC_ALL, "fr_FR.ISO8859-1"); 
 
    for (i = 0; i < NUM_OF_DATES; i++) { 
        /* Convert to a tm structure */ 
        tm_ptr = localtime(&time_list[i]); 
 
        /* Format the date and time */ 
        count = strftime(buffer, BUF_SIZE, 
               "Date: %A %d %B %Y%nTime: %T%n%n", tm_ptr); 
        if (count == 0) { 
            perror("strftime"); 
            exit(EXIT_FAILURE); 
        } 
 
        /* Print the result */ 
        printf(buffer); 
    } 
} 

Running the example program produces the following result:


Using the C locale: 
 
Date: Thursday 01 January 1970 
Time: 00:08:20 
 
Date: Tuesday 29 February 1972 
Time: 08:26:40 
 
Date: Tuesday 31 December 1991 
Time: 23:59:59 
 
Date: Wednesday 01 January 1992 
Time: 00:00:00 
 
Date: Sunday 03 May 1992 
Time: 13:33:20 
 
Date: Monday 04 May 1992 
Time: 17:20:00 
 
Date: Friday 15 May 1992 
Time: 03:20:00 
 
 
Using the fr_FR.ISO8859-1 locale: 
 
Date: jeudi 01 janvier 1970 
Time: 00:08:20 
 
Date: mardi 29 février 1972 
Time: 08:26:40 
 
Date: mardi 31 décembre 1991 
Time: 23:59:59 
 
Date: mercredi 01 janvier 1992 
Time: 00:00:00 
 
Date: dimanche 03 mai 1992 
Time: 13:33:20 
 
Date: lundi 04 mai 1992 
Time: 17:20:00 
 
Date: vendredi 15 mai 1992 
Time: 03:20:00 


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