CURLOPT_NETRC(3) Introduction to Library Functions CURLOPT_NETRC(3)

CURLOPT_NETRC - enable use of .netrc

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_NETRC, long level);

This parameter controls the preference level of libcurl between using usernames and passwords from your ~/.netrc file, relative to usernames and passwords in the URL supplied with CURLOPT_URL(3).

On Windows, libcurl primarily checks for .netrc in %HOME%. If %HOME% is not set on Windows, libcurl falls back to %USERPROFILE%. If the file does not exist, it falls back to check if there is instead a file named _netrc - using an underscore instead of period.

You can also tell libcurl a different filename to use with CURLOPT_NETRC_FILE(3).

libcurl uses a username (and supplied or prompted password) supplied with CURLOPT_USERPWD(3) or CURLOPT_USERNAME(3) in preference to any of the options controlled by this parameter.

Only machine name, username and password are taken into account (init macros and similar things are not supported).

libcurl does not verify that the file has the correct properties set (as the standard Unix ftp client does). It should only be readable by user.

level is a long that should be set to one of the values described below.

libcurl ignores the .netrc file. This is the default.
The use of the .netrc file is optional, and information in the URL is to be preferred. The file is scanned for the host and username (to find the password only) or for the host only, to find the first username and password after that machine, which ever information is not specified.
The use of the .netrc file is required, and any credential information present in the URL is ignored. The file is scanned for the host and username (to find the password only) or for the host only, to find the first username and password after that machine, which ever information is not specified.

The .netrc file format is simple: you specify lines with a machine name and follow the login and password that are associated with that machine.

Each field is provided as a sequence of letters that ends with a space or newline. Starting in 7.84.0, libcurl also supports quoted strings. They start and end with double quotes and support the escaped special letters ", n, r, and t. Quoted strings are the only way a space character can be used in a username or password.

Provides credentials for a host called name. libcurl searches the .netrc file for a machine token that matches the hostname specified in the URL. Once a match is made, the subsequent tokens are processed, stopping when the end of file is reached or another "machine" is encountered.
This is the same as machine name except that default matches any name. There can be only one default token, and it must be after all machine tokens. To provide a default anonymous login for hosts that are not otherwise matched, add a line similar to this in the end: 

default login anonymous password user@domain
The username string for the remote machine.
Supply a password. If this token is present, curl supplies the specified string if the remote server requires a password as part of the login process. Note that if this token is present in the .netrc file you really should make sure the file is not readable by anyone besides the user.
Define a macro. This feature is not supported by libcurl. In order for the rest of the .netrc to still work fine, libcurl properly skips every definition done with "macdef" that it finds.

CURL_NETRC_IGNORED

This functionality affects all supported protocols

int main(void)
{


  CURL *curl = curl_easy_init();


  if(curl) {


    CURLcode ret;


    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/");


    curl_easy_setopt(curl, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);


    ret = curl_easy_perform(curl);


  }
}

Added in curl 7.1

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLOPT_NETRC_FILE(3), CURLOPT_USERNAME(3), CURLOPT_USERPWD(3)

2025-05-02 libcurl