Perl Requires Chilkat v11.5.0+

curl with Variable Substitution in a GraphQL Request Body

See more CURL Examples

This example shows how to use variables inside a graphql request body using the {{variable_name}} syntax. When the HTTP request’s Content-Type indicates graphql, Chilkat automatically applies proper escaping to each substituted value, ensuring the resulting graphql remains valid. Perl

use chilkat();

$success = 0;

$success = 0;

#  Variable names are enclosed between {{ and }}
#  Important: Variables should be placed inside the quotes.

#  curl -X POST https://api.example.com/graphql \
#    -H "Content-Type: application/graphql; charset=utf-8" \
#    -H "Accept: application/json" \
#    --data-binary "mutation {
#    createUser(
#      input: {
#        name: \"{{name}}\"
#        city: \"{{city}}\"
#        note: \"{{note}}\"
#        bio: \"{{bio}}\"
#      }
#    ) {
#      id
#      name
#    }
#  }"

#  Build the above curl command.
$sbCurl = chilkat::CkStringBuilder->new();
$sbCurl->AppendLn("curl -X POST https://api.example.com/graphql \\");
$sbCurl->AppendLn("  -H \"Content-Type: application/graphql; charset=utf-8\" \\");
$sbCurl->AppendLn("  -H \"Accept: application/json\" \\");
$sbCurl->AppendLn("  -d \"mutation {");
$sbCurl->AppendLn("  createUser(");
$sbCurl->AppendLn("    input: {");
$sbCurl->AppendLn("      name: \\\"{{name}}\\\"");
$sbCurl->AppendLn("      city: \\\"{{city}}\\\"");
$sbCurl->AppendLn("      note: \\\"{{note}}\\\"");
$sbCurl->AppendLn("      bio: \\\"{{bio}}\\\"");
$sbCurl->AppendLn("    }");
$sbCurl->AppendLn("  ) {");
$sbCurl->AppendLn("    id");
$sbCurl->AppendLn("    name");
$sbCurl->AppendLn("  }");
$sbCurl->AppendLn("}\"");

$curl = chilkat::CkHttpCurl->new();

#  Provide values for variables
$curl->SetVar("name","José O'Connor");
$curl->SetVar("city","München");
$curl->SetVar("note","He said \"Hello, world!\" — and left…");
$curl->SetVar("bio","Loves sushi, café visits, and π ≈ 3.14159");

#  To demonstrate how the variables are replaced, this example does not execute the curl command. 
#  Instead, it generates the raw HTTP request that would be sent if the curl command were run.
$sbRawRequest = chilkat::CkStringBuilder->new();
$success = $curl->ToRawRequest($sbCurl->getAsString(),$sbRawRequest);
if ($success == 0) {
    print $curl->lastErrorText() . "\r\n";
    exit;
}

print $sbRawRequest->getAsString() . "\r\n";

#  The output is shown below.
#  Notice the quote chars around "Hello, world!" are properly escaped.

#  POST /graphql HTTP/1.1
#  Accept: application/json
#  Host: api.example.com
#  Content-Type: application/graphql; charset=utf-8
#  Content-Length: 250
#  
#  mutation {
#    createUser(
#      input: {
#        name: "José O'Connor"
#        city: "München"
#        note: "He said \"Hello, world!\" — and left…"
#        bio: "Loves sushi, café visits, and π ≈ 3.14159"
#      }
#    ) {
#      id
#      name
#    }
#  }