docs/libcurl/libcurl-env.3 - platform/external/curl - Git at Google

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 .\" *
 .\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
 .\" * are also available at https://curl.se/docs/copyright.html.
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 .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 .\" * copies of the Software, and permit persons to whom the Software is
 .\" * furnished to do so, under the terms of the COPYING file.
 .\" *
 .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 .\" * KIND, either express or implied.
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 .\" * SPDX-License-Identifier: curl
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 .\" **************************************************************************
 .TH libcurl-env 3 "20 January 2018" "libcurl 7.58.0" "libcurl environment variables"
 .SH NAME
 libcurl-env \- environment variables libcurl understands
 .SH DESCRIPTION
 libcurl reads and understands a set of environment variables that if set will
 control and change behaviors. This is the full list of variables to set and
 description of what they do. Also note that curl, the command line tool,
 supports a set of additional environment variables independently of this.
 .IP "[scheme]_proxy"
 When libcurl is given a URL to use in a transfer, it first extracts the
 "scheme" part from the URL and checks if there is a given proxy set for that
 in its corresponding environment variable. A URL like "https://example.com"
 will hence use the "http_proxy" variable, while a URL like "ftp://example.com"
 will use the "ftp_proxy" variable.

 These proxy variables are also checked for in their uppercase versions, except
 the "http_proxy" one which is only used lowercase. Note also that some systems
 actually have a case insensitive handling of environment variables and then of
 course "HTTP_PROXY" will still work...
 .IP ALL_PROXY
 This is a setting to set proxy for all URLs, independently of what scheme is
 being used. Note that the scheme specific variables will override this one if
 set.
 .IP CURL_SSL_BACKEND
 When libcurl is built to support multiple SSL backends, it will select a
 specific backend at first use. If no selection is done by the program using
 libcurl, this variable's selection will be used. Setting a name that is not a
 built-in alternative will make libcurl stay with the default.

 SSL backend names (case-insensitive): BearSSL, GnuTLS, gskit, mbedTLS,
 nss, OpenSSL, rustls, Schannel, Secure-Transport, wolfSSL
 .IP HOME
 When the netrc feature is used (\fICURLOPT_NETRC(3)\fP), this variable is
 checked as the primary way to find the "current" home directory in which
 the .netrc file is likely to exist.
 .IP USERPROFILE
 When the netrc feature is used (\fICURLOPT_NETRC(3)\fP), this variable is
 checked as the secondary way to find the "current" home directory (on Windows
 only) in which the .netrc file is likely to exist.
 .IP LOGNAME
 User name to use when invoking the \fIntlm-wb\fP tool, if \fINTLMUSER\fP was
 not set.
 .IP NO_PROXY
 This has the same functionality as the \fICURLOPT_NOPROXY(3)\fP option: it
 gives libcurl a comma-separated list of host name patterns for which libcurl
 should not use a proxy.
 .IP NTLMUSER
 User name to use when invoking the \fIntlm-wb\fP tool.
 .IP SSLKEYLOGFILE
 When set and libcurl runs with a SSL backend that supports this feature,
 libcurl will save SSL secrets into the given file name. Using those SSL
 secrets, other tools (such as Wireshark) can decrypt the SSL communication and
 analyze/view the traffic.
 .IP SSL_DIR
 When libcurl runs with the NSS backends for TLS features, this variable is
 used to find the directory for NSS PKI database instead of the built-in.
 .IP USER
 User name to use when invoking the \fIntlm-wb\fP tool, if \fINTLMUSER\fP and
 \fILOGNAME\fP were not set.
 .SH "Debug Variables"
 There's a set of variables only recognized and used if libcurl was built
 "debug enabled", which should never be true for a library used in production.
 .IP "CURL_GETHOSTNAME"
 Debug-only variable.
 .IP "CURL_FORCETIME"
 Debug-only variable.
 .IP "CURL_ENTROPY"
 Debug-only variable. Used to set a fixed faked value to use instead of a
 proper random number so that functions in libcurl that are otherwise getting
 random outputs can be tested for what they generate.
 .IP "CURL_TRACE"
 Debug-only variable. Used for debugging the lib/ldap implementation.
 .IP "CURL_NTLM_WB_FILE"
 Debug-only variable. Used to set to a debug-version of the \fIntlm-wb\fP
 executable.
 .IP "CURL_OPENLDAP_TRACE"
 Debug-only variable. Used for debugging the OpenLDAP implementation.
	.\" **************************************************************************
	.\" * _ _ ____ _
	.\" * Project ___\| \| \| \| _ \\| \|
	.\" * / __\| \| \| \| \|_) \| \|
	.\" * \| (__\| \|_\| \| _ <\| \|___
	.\" * \___\|\___/\|_\| \_\_____\|
	.\" *
	.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
	.\" *
	.\" * This software is licensed as described in the file COPYING, which
	.\" * you should have received as part of this distribution. The terms
	.\" * are also available at https://curl.se/docs/copyright.html.
	.\" *
	.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
	.\" * copies of the Software, and permit persons to whom the Software is
	.\" * furnished to do so, under the terms of the COPYING file.
	.\" *
	.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
	.\" * KIND, either express or implied.
	.\" *
	.\" * SPDX-License-Identifier: curl
	.\" *
	.\" **************************************************************************
	.TH libcurl-env 3 "20 January 2018" "libcurl 7.58.0" "libcurl environment variables"
	.SH NAME
	libcurl-env \- environment variables libcurl understands
	.SH DESCRIPTION
	libcurl reads and understands a set of environment variables that if set will
	control and change behaviors. This is the full list of variables to set and
	description of what they do. Also note that curl, the command line tool,
	supports a set of additional environment variables independently of this.
	.IP "[scheme]_proxy"
	When libcurl is given a URL to use in a transfer, it first extracts the
	"scheme" part from the URL and checks if there is a given proxy set for that
	in its corresponding environment variable. A URL like "https://example.com"
	will hence use the "http_proxy" variable, while a URL like "ftp://example.com"
	will use the "ftp_proxy" variable.

	These proxy variables are also checked for in their uppercase versions, except
	the "http_proxy" one which is only used lowercase. Note also that some systems
	actually have a case insensitive handling of environment variables and then of
	course "HTTP_PROXY" will still work...
	.IP ALL_PROXY
	This is a setting to set proxy for all URLs, independently of what scheme is
	being used. Note that the scheme specific variables will override this one if
	set.
	.IP CURL_SSL_BACKEND
	When libcurl is built to support multiple SSL backends, it will select a
	specific backend at first use. If no selection is done by the program using
	libcurl, this variable's selection will be used. Setting a name that is not a
	built-in alternative will make libcurl stay with the default.

	SSL backend names (case-insensitive): BearSSL, GnuTLS, gskit, mbedTLS,
	nss, OpenSSL, rustls, Schannel, Secure-Transport, wolfSSL
	.IP HOME
	When the netrc feature is used (\fICURLOPT_NETRC(3)\fP), this variable is
	checked as the primary way to find the "current" home directory in which
	the .netrc file is likely to exist.
	.IP USERPROFILE
	When the netrc feature is used (\fICURLOPT_NETRC(3)\fP), this variable is
	checked as the secondary way to find the "current" home directory (on Windows
	only) in which the .netrc file is likely to exist.
	.IP LOGNAME
	User name to use when invoking the \fIntlm-wb\fP tool, if \fINTLMUSER\fP was
	not set.
	.IP NO_PROXY
	This has the same functionality as the \fICURLOPT_NOPROXY(3)\fP option: it
	gives libcurl a comma-separated list of host name patterns for which libcurl
	should not use a proxy.
	.IP NTLMUSER
	User name to use when invoking the \fIntlm-wb\fP tool.
	.IP SSLKEYLOGFILE
	When set and libcurl runs with a SSL backend that supports this feature,
	libcurl will save SSL secrets into the given file name. Using those SSL
	secrets, other tools (such as Wireshark) can decrypt the SSL communication and
	analyze/view the traffic.
	.IP SSL_DIR
	When libcurl runs with the NSS backends for TLS features, this variable is
	used to find the directory for NSS PKI database instead of the built-in.
	.IP USER
	User name to use when invoking the \fIntlm-wb\fP tool, if \fINTLMUSER\fP and
	\fILOGNAME\fP were not set.
	.SH "Debug Variables"
	There's a set of variables only recognized and used if libcurl was built
	"debug enabled", which should never be true for a library used in production.
	.IP "CURL_GETHOSTNAME"
	Debug-only variable.
	.IP "CURL_FORCETIME"
	Debug-only variable.
	.IP "CURL_ENTROPY"
	Debug-only variable. Used to set a fixed faked value to use instead of a
	proper random number so that functions in libcurl that are otherwise getting
	random outputs can be tested for what they generate.
	.IP "CURL_TRACE"
	Debug-only variable. Used for debugging the lib/ldap implementation.
	.IP "CURL_NTLM_WB_FILE"
	Debug-only variable. Used to set to a debug-version of the \fIntlm-wb\fP
	executable.
	.IP "CURL_OPENLDAP_TRACE"
	Debug-only variable. Used for debugging the OpenLDAP implementation.