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        !            22: .TH curl_global_init 3 "January 23, 2020" "libcurl 7.70.0" "libcurl Manual"
        !            23: 
        !            24: .SH NAME
        !            25: curl_global_init - Global libcurl initialisation
        !            26: .SH SYNOPSIS
        !            27: .B #include <curl/curl.h>
        !            28: .sp
        !            29: .BI "CURLcode curl_global_init(long " flags ");"
        !            30: .ad
        !            31: .SH DESCRIPTION
        !            32: This function sets up the program environment that libcurl needs.  Think of it
        !            33: as an extension of the library loader.
        !            34: 
        !            35: This function must be called at least once within a program (a program is all
        !            36: the code that shares a memory space) before the program calls any other
        !            37: function in libcurl.  The environment it sets up is constant for the life of
        !            38: the program and is the same for every program, so multiple calls have the same
        !            39: effect as one call.
        !            40: 
        !            41: The flags option is a bit pattern that tells libcurl exactly what features to
        !            42: init, as described below. Set the desired bits by ORing the values together.
        !            43: In normal operation, you must specify CURL_GLOBAL_ALL.  Don't use any other
        !            44: value unless you are familiar with it and mean to control internal operations of
        !            45: libcurl.
        !            46: 
        !            47: \fBThis function is not thread safe.\fP You must not call it when any other
        !            48: thread in the program (i.e. a thread sharing the same memory) is running.
        !            49: This doesn't just mean no other thread that is using libcurl.  Because
        !            50: \fIcurl_global_init(3)\fP calls functions of other libraries that are
        !            51: similarly thread unsafe, it could conflict with any other thread that uses
        !            52: these other libraries.
        !            53: 
        !            54: If you are initializing libcurl from a Windows DLL you should not initialize it
        !            55: from DllMain or a static initializer because Windows holds the loader lock
        !            56: during that time and it could cause a deadlock.
        !            57: 
        !            58: See the description in \fIlibcurl(3)\fP of global environment requirements for
        !            59: details of how to use this function.
        !            60: .SH FLAGS
        !            61: .IP CURL_GLOBAL_ALL
        !            62: Initialize everything possible. This sets all known bits except
        !            63: \fBCURL_GLOBAL_ACK_EINTR\fP.
        !            64: 
        !            65: .IP CURL_GLOBAL_SSL
        !            66: (This flag's presence or absence serves no meaning since 7.57.0. The
        !            67: description below is for older libcurl versions.)
        !            68: 
        !            69: Initialize SSL.
        !            70: 
        !            71: The implication here is that if this bit is not set, the initialization of the
        !            72: SSL layer needs to be done by the application or at least outside of
        !            73: libcurl. The exact procedure how to do SSL initialization depends on the TLS
        !            74: backend libcurl uses.
        !            75: 
        !            76: Doing TLS based transfers without having the TLS layer initialized may lead to
        !            77: unexpected behaviors.
        !            78: .IP CURL_GLOBAL_WIN32
        !            79: Initialize the Win32 socket libraries.
        !            80: 
        !            81: The implication here is that if this bit is not set, the initialization of
        !            82: winsock has to be done by the application or you risk getting undefined
        !            83: behaviors. This option exists for when the initialization is handled outside
        !            84: of libcurl so there's no need for libcurl to do it again.
        !            85: .IP CURL_GLOBAL_NOTHING
        !            86: Initialise nothing extra. This sets no bit.
        !            87: .IP CURL_GLOBAL_DEFAULT
        !            88: A sensible default. It will init both SSL and Win32. Right now, this equals
        !            89: the functionality of the \fBCURL_GLOBAL_ALL\fP mask.
        !            90: .IP CURL_GLOBAL_ACK_EINTR
        !            91: This bit has no point since 7.69.0 but its behavior is instead the default.
        !            92: 
        !            93: Before 7.69.0: when this flag is set, curl will acknowledge EINTR condition
        !            94: when connecting or when waiting for data.  Otherwise, curl waits until full
        !            95: timeout elapses. (Added in 7.30.0)
        !            96: .SH RETURN VALUE
        !            97: If this function returns non-zero, something went wrong and you cannot use the
        !            98: other curl functions.
        !            99: .SH "SEE ALSO"
        !           100: .BR curl_global_init_mem "(3), "
        !           101: .BR curl_global_cleanup "(3), "
        !           102: .BR curl_global_sslset "(3), "
        !           103: .BR curl_easy_init "(3) "
        !           104: .BR libcurl "(3) "