Generating code coverage in headless mode using the collector

To run code coverage in headless mode using the code coverage collector, start the collector and run the application with settings specified to connect to the code coverage daemon. The daemon listens on one or more ports, waiting for incoming code coverage sessions.

Before you begin

Notes:

The headless code coverage collector is not available on macOS.
By default, results are stored in the home directory of the user that started the headless code coverage collector in a directory called CC. This location can be overridden by using the -o,output parameter. For a syntax diagram and a complete list of options, see Starting and stopping the headless code coverage collector.

Procedure

Start the headless code coverage collector. The code coverage daemon starts and assigns a port number. The daemon then echoes the port on the console via message CRRDG7026, echoes the process ID of the code coverage headless collector via message CRRD7027, and waits for a connection.
```
> codecov -startdaemon
```
Note:
- You can specify a port number or a range of port numbers with -p,port: codecov -startdaemon -port=8009 or codecov -d -p=8009-8109.
- If you are running headless code coverage on Windows or Linux, the executables are in the headless-cc subdirectory where you installed the product.
- If you are running headless code coverage on z/OS®, use the ccstart.sh script in /usr/lpp/IBM/debug/headless-code-coverage/bin/ directly to start a code coverage daemon.
- You can start multiple daemons each having different options, so long as unique port numbers are used.
Configure for code coverage with either a debug profile or the TEST runtime option:
- Create and activate a debug profile in code coverage mode. See Managing debug profiles with the z/OS Debugger Profiles view.
- Specify a TEST runtime option with IP name or address and port number assigned to the headless code coverage collector, along with a code coverage startup key. You can find examples in the TEST runtime option examples for code coverage table and a complete syntax in Syntax of the TEST runtime option. For example, to submit JCL to the daemon, you can specify as below:
```
//CEEOPTS DD *
TEST(,,,TCPIP&&9.2.5.23%64402:*)
ENVAR("EQA_STARTUP_KEY=CC")
/*
```
Start the application. When code coverage is completed, a message is displayed to indicate the results of the code coverage run.
To stop the code coverage daemon, specify > codecov -stopdaemon=<port>. For example, to stop the code coverage daemon running on port 8009, specify > codecov -D=<port>. If you are using headless code coverage on z/OS, you can use the ccstop.sh script in /usr/lpp/IBM/debug/headless-code-coverage/bin/.

Note: You can also stop the code coverage daemon by pressing ctrl-c or ctrl-break on the command line. Stopping the daemon with this method skips the cleanup function and might result in working directories in the output directory. The working directories that appear as folders with long numbers as the names can be safely deleted when no code coverage daemon is running.