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| .TH NEWLOCALE 3 2021-03-22 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| newlocale, freelocale \- create, modify, and free a locale object |
| .SH SYNOPSIS |
| .nf |
| .B #include <locale.h> |
| .PP |
| .BI "locale_t newlocale(int " category_mask ", const char *" locale , |
| .BI " locale_t " base ); |
| .BI "void freelocale(locale_t " locobj ); |
| .fi |
| .PP |
| .RS -4 |
| Feature Test Macro Requirements for glibc (see |
| .BR feature_test_macros (7)): |
| .RE |
| .PP |
| .BR newlocale (), |
| .BR freelocale (): |
| .nf |
| Since glibc 2.10: |
| _XOPEN_SOURCE >= 700 |
| Before glibc 2.10: |
| _GNU_SOURCE |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR newlocale () |
| function creates a new locale object, or modifies an existing object, |
| returning a reference to the new or modified object as the function result. |
| Whether the call creates a new object or modifies an existing object |
| is determined by the value of |
| .IR base : |
| .IP * 3 |
| If |
| .I base |
| is |
| .IR "(locale_t)\ 0" , |
| a new object is created. |
| .IP * |
| If |
| .I base |
| refers to valid existing locale object |
| (i.e., an object returned by a previous call to |
| .BR newlocale () |
| or |
| .BR duplocale (3)), |
| then that object is modified by the call. |
| If the call is successful, the contents of |
| .I base |
| are unspecified (in particular, the object referred to by |
| .I base |
| may be freed, and a new object created). |
| Therefore, the caller should ensure that it stops using |
| .I base |
| before the call to |
| .BR newlocale (), |
| and should subsequently refer to the modified object via the |
| reference returned as the function result. |
| If the call fails, the contents of |
| .I base |
| remain valid and unchanged. |
| .PP |
| If |
| .I base |
| is the special locale object |
| .BR LC_GLOBAL_LOCALE |
| (see |
| .BR duplocale (3)), |
| or is not |
| .IR "(locale_t)\ 0" |
| and is not a valid locale object handle, |
| the behavior is undefined. |
| .PP |
| The |
| .I category_mask |
| argument is a bit mask that specifies the locale categories |
| that are to be set in a newly created locale object |
| or modified in an existing object. |
| The mask is constructed by a bitwise OR of the constants |
| .BR LC_ADDRESS_MASK , |
| .BR LC_CTYPE_MASK , |
| .BR LC_COLLATE_MASK , |
| .BR LC_IDENTIFICATION_MASK , |
| .BR LC_MEASUREMENT_MASK , |
| .BR LC_MESSAGES_MASK , |
| .BR LC_MONETARY_MASK , |
| .BR LC_NUMERIC_MASK , |
| .BR LC_NAME_MASK , |
| .BR LC_PAPER_MASK , |
| .BR LC_TELEPHONE_MASK , |
| and |
| .BR LC_TIME_MASK . |
| Alternatively, the mask can be specified as |
| .BR LC_ALL_MASK , |
| which is equivalent to ORing all of the preceding constants. |
| .PP |
| For each category specified in |
| .IR category_mask , |
| the locale data from |
| .I locale |
| will be used in the object returned by |
| .BR newlocale (). |
| If a new locale object is being created, |
| data for all categories not specified in |
| .IR category_mask |
| is taken from the default ("POSIX") locale. |
| .PP |
| The following preset values of |
| .I locale |
| are defined for all categories that can be specified in |
| .IR category_mask : |
| .TP |
| "POSIX" |
| A minimal locale environment for C language programs. |
| .TP |
| "C" |
| Equivalent to "POSIX". |
| .TP |
| "" |
| An implementation-defined native environment |
| corresponding to the values of the |
| .BR LC_* |
| and |
| .B LANG |
| environment variables (see |
| .BR locale (7)). |
| .SS freelocale() |
| The |
| .BR freelocale () |
| function deallocates the resources associated with |
| .IR locobj , |
| a locale object previously returned by a call to |
| .BR newlocale () |
| or |
| .BR duplocale (3). |
| If |
| .I locobj |
| is |
| .BR LC_GLOBAL_LOCALE |
| or is not valid locale object handle, the results are undefined. |
| .PP |
| Once a locale object has been freed, |
| the program should make no further use of it. |
| .SH RETURN VALUE |
| On success, |
| .BR newlocale () |
| returns a handle that can be used in calls to |
| .BR duplocale (3), |
| .BR freelocale (), |
| and other functions that take a |
| .I locale_t |
| argument. |
| On error, |
| .BR newlocale () |
| returns |
| .IR "(locale_t)\ 0", |
| and sets |
| .I errno |
| to indicate the error. |
| .SH ERRORS |
| .TP |
| .B EINVAL |
| One or more bits in |
| .I category_mask |
| do not correspond to a valid locale category. |
| .TP |
| .B EINVAL |
| .I locale |
| is NULL. |
| .TP |
| .B ENOENT |
| .I locale |
| is not a string pointer referring to a valid locale. |
| .TP |
| .B ENOMEM |
| Insufficient memory to create a locale object. |
| .SH VERSIONS |
| The |
| .BR newlocale () |
| and |
| .BR freelocale () |
| functions first appeared in version 2.3 of the GNU C library. |
| .SH CONFORMING TO |
| POSIX.1-2008. |
| .SH NOTES |
| Each locale object created by |
| .BR newlocale () |
| should be deallocated using |
| .BR freelocale (). |
| .SH EXAMPLES |
| The program below takes up to two command-line arguments, |
| which each identify locales. |
| The first argument is required, and is used to set the |
| .B LC_NUMERIC |
| category in a locale object created using |
| .BR newlocale (). |
| The second command-line argument is optional; |
| if it is present, it is used to set the |
| .B LC_TIME |
| category of the locale object. |
| .PP |
| Having created and initialized the locale object, |
| the program then applies it using |
| .BR uselocale (3), |
| and then tests the effect of the locale changes by: |
| .IP 1. 3 |
| Displaying a floating-point number with a fractional part. |
| This output will be affected by the |
| .B LC_NUMERIC |
| setting. |
| In many European-language locales, |
| the fractional part of the number is separated from the integer part |
| using a comma, rather than a period. |
| .IP 2. |
| Displaying the date. |
| The format and language of the output will be affected by the |
| .B LC_TIME |
| setting. |
| .PP |
| The following shell sessions show some example runs of this program. |
| .PP |
| Set the |
| .B LC_NUMERIC |
| category to |
| .IR fr_FR |
| (French): |
| .PP |
| .in +4n |
| .EX |
| $ \fB./a.out fr_FR\fP |
| 123456,789 |
| Fri Mar 7 00:25:08 2014 |
| .EE |
| .in |
| .PP |
| Set the |
| .B LC_NUMERIC |
| category to |
| .IR fr_FR |
| (French), |
| and the |
| .B LC_TIME |
| category to |
| .IR it_IT |
| (Italian): |
| .PP |
| .in +4n |
| .EX |
| $ \fB./a.out fr_FR it_IT\fP |
| 123456,789 |
| ven 07 mar 2014 00:26:01 CET |
| .EE |
| .in |
| .PP |
| Specify the |
| .B LC_TIME |
| setting as an empty string, |
| which causes the value to be taken from environment variable settings |
| (which, here, specify |
| .IR mi_NZ , |
| New Zealand Māori): |
| .PP |
| .in +4n |
| .EX |
| $ LC_ALL=mi_NZ ./a.out fr_FR "" |
| 123456,789 |
| Te Paraire, te 07 o Poutū\-te\-rangi, 2014 00:38:44 CET |
| .EE |
| .in |
| .SS Program source |
| .EX |
| #define _XOPEN_SOURCE 700 |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <locale.h> |
| #include <time.h> |
| |
| #define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \e |
| } while (0) |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| char buf[100]; |
| time_t t; |
| size_t s; |
| struct tm *tm; |
| locale_t loc, nloc; |
| |
| if (argc < 2) { |
| fprintf(stderr, "Usage: %s locale1 [locale2]\en", argv[0]); |
| exit(EXIT_FAILURE); |
| } |
| |
| /* Create a new locale object, taking the LC_NUMERIC settings |
| from the locale specified in argv[1]. */ |
| |
| loc = newlocale(LC_NUMERIC_MASK, argv[1], (locale_t) 0); |
| if (loc == (locale_t) 0) |
| errExit("newlocale"); |
| |
| /* If a second command\-line argument was specified, modify the |
| locale object to take the LC_TIME settings from the locale |
| specified in argv[2]. We assign the result of this newlocale() |
| call to \(aqnloc\(aq rather than \(aqloc\(aq, since in some cases, we might |
| want to preserve \(aqloc\(aq if this call fails. */ |
| |
| if (argc > 2) { |
| nloc = newlocale(LC_TIME_MASK, argv[2], loc); |
| if (nloc == (locale_t) 0) |
| errExit("newlocale"); |
| loc = nloc; |
| } |
| |
| /* Apply the newly created locale to this thread. */ |
| |
| uselocale(loc); |
| |
| /* Test effect of LC_NUMERIC. */ |
| |
| printf("%8.3f\en", 123456.789); |
| |
| /* Test effect of LC_TIME. */ |
| |
| t = time(NULL); |
| tm = localtime(&t); |
| if (tm == NULL) |
| errExit("time"); |
| |
| s = strftime(buf, sizeof(buf), "%c", tm); |
| if (s == 0) |
| errExit("strftime"); |
| |
| printf("%s\en", buf); |
| |
| /* Free the locale object. */ |
| |
| uselocale(LC_GLOBAL_HANDLE); /* So \(aqloc\(aq is no longer in use */ |
| freelocale(loc); |
| |
| exit(EXIT_SUCCESS); |
| } |
| .EE |
| .SH SEE ALSO |
| .BR locale (1), |
| .BR duplocale (3), |
| .BR setlocale (3), |
| .BR uselocale (3), |
| .BR locale (5), |
| .BR locale (7) |