Tcl Requires Chilkat v11.5.0+

curl with Variable Substitution in the Request Body

See more CURL Examples

This example demonstrates using variables located in the request body with the {{variable_name}} syntax. Tcl

load ./chilkat.dll

set success 0

#  Variables can also be used within the HTTP request body.
#  Variable names are enclosed between {{ and }}

#  Here is a curl command with two variables {{name}} and {{age}} located in the data.

#  curl -X POST https://api.example.com/data \
#    -H "Content-Type: application/json" \
#    -d '{"name":"{{name}}","age":{{age}}}'

set sbCurl [new_CkStringBuilder]

CkStringBuilder_AppendLn $sbCurl "curl -X POST https://api.example.com/data \\"
CkStringBuilder_AppendLn $sbCurl "  -H \"Content-Type: application/json\" \\"
CkStringBuilder_AppendLn $sbCurl "  -d '{\"name\":\"{{name}}\",\"age\":{{age}}}'"

set curl [new_CkHttpCurl]

#  Provide values for variables.
CkHttpCurl_SetVar $curl "name" "Alice"
CkHttpCurl_SetVar $curl "age" "30"

#  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.
set sbRawRequest [new_CkStringBuilder]

set success [CkHttpCurl_ToRawRequest $curl [CkStringBuilder_getAsString $sbCurl] $sbRawRequest]
if {$success == 0} then {
    puts [CkHttpCurl_lastErrorText $curl]
    delete_CkStringBuilder $sbCurl
    delete_CkHttpCurl $curl
    delete_CkStringBuilder $sbRawRequest
    exit
}

puts [CkStringBuilder_getAsString $sbRawRequest]

#  Output:

#  POST /data HTTP/1.1
#  Host: api.example.com
#  Content-Type: application/json
#  Content-Length: 25
#  
#  {"name":"Alice","age":30}

#  --------------------------------------------------------------------------------------------------
#  Note: Variable substitution in the request body can be turned off by 
#  setting the EnableBodyVars property equal to 0

CkHttpCurl_put_EnableBodyVars $curl 0

set success [CkHttpCurl_ToRawRequest $curl [CkStringBuilder_getAsString $sbCurl] $sbRawRequest]
if {$success == 0} then {
    puts [CkHttpCurl_lastErrorText $curl]
    delete_CkStringBuilder $sbCurl
    delete_CkHttpCurl $curl
    delete_CkStringBuilder $sbRawRequest
    exit
}

puts [CkStringBuilder_getAsString $sbRawRequest]

#  The raw request with body variable substitution disable:

#  Host: api.example.com
#  Content-Type: application/json
#  Content-Length: 33
#  
#  {"name":"{{name}}","age":{{age}}}

delete_CkStringBuilder $sbCurl
delete_CkHttpCurl $curl
delete_CkStringBuilder $sbRawRequest