Red Hat Developer Toolset

In this step, you will configure your system to obtain software, including the RHDTS, latest dynamic languages, and open source databases from the Red Hat Software Collection (RHSCL) repository by using the command line interface. 

You can add or remove software repositories from the command line using the subscription-manager tool as the root user. Use the --list option to view the available software repositories and verify that you have access to RHSCL, which includes RHDTS:

$ su -
# subscription-manager repos --list | egrep rhscl

If you don’t see any RHSCL repositories in the list, your subscription might not include it. See Troubleshooting and FAQ for more information.

If you are using a desktop edition of RHEL, change -server- to -desktop- in the following commands:

# subscription-manager repos --list
# subscription-manager repos --enable rhel-7-server-optional-rpms

In this next step you will use a single command to download and install GCC 8.2, and other development tools that are part of RHDTS. The length of time this step takes depends on the speed of your Internet connection and your system. With a reasonably fast connection, this step should complete in well under 5 minutes.

To install all components, type:

$ su -
# yum install devtoolset-8

If you want to install a subset of components, see the instructions here.

Note: You will still use devtoolset-8 as the name of the software collection in all scl commands. Only the name of the meta-package to be installed by yum changes.

Using DTS C++ from the command line

The GNU C++ compiler is run with the command, g++. You need to add RHDTS to your environment with scl enable in a Terminal window. Also see Permanently adding DTS to your Development Environment for more information.

$ scl enable devtoolset-8 bash

Now create hello.cpp using a text editor such as vi, nano, or gedit with the following content:

hello.cpp

#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {
  cout << "Hello, Red Hat Developer Program World!" << endl;
  return 0;
}

Now compile and run the program:

$ g++ -o hello hello.cpp
$ ./hello
Hello, Red Hat Developer Program World!

For more information, see the GNU C++ Compiler section of the Red Hat Developer Toolset 8 User Guide.

Docker-formatted container images

Docker-formatted container images can be used to run RHDTS components inside virtual software containers, thus isolating them from the host system and allowing for their rapid deployment. For detailed description of the RHDTS docker-formatted container images and RHDTS dockerfiles, see Using Red Hat Software Collections Container Images.

Working with the Red Hat Developer Toolset and Software Collection packages

The RHDTS is delivered as a set of packages in the Red Hat Software Collection (RHSCL). The software packages in RHSCL are designed to allow multiple versions of software to be installed concurrently. To accomplish this, the desired package is added to your runtime environment as needed with the scl enable command. When scl enable runs, it modifies environment variables and then runs the specified command. The environmental changes only affect the command that is run by scl and any processes that are run from that command. The steps in this tutorial run the command bash to start a new interactive shell to work in the updated environment. The changes aren’t permanent. Typing exit will return to the original shell with the original environment. Each time you login, or start a new terminal session, scl enable needs to be run again.

While it is possible to change the system profile to make RHSCL packages part of the system’s global environment, this is not recommended. Doing this can cause conflicts and unexpected problems with other applications because the system version of the package is obscured by having the RHSCL version in the path first.

Permanently adding DTS to your development environment

To make RHDTS a permanent part of your development environment, you can add it to the login script for your specific user ID. This is the recommend approach for development, because only processes run under your user ID will be affected.

Using your preferred text editor, add the following line to the end of ~/.bashrc:

source scl_source enable devtoolset-8

After logging out and logging back in again, you can verify that the RHDTS GCC is in your path by running which g++ or g++ --version.

$ which g++
/opt/rh/devtoolset-4/root/usr/bin/g++

$ g++ -v
g++ (GCC) 8.2 20181112 (Red Hat 8.2.1-0)

In this step, you will configure your system to obtain software, including the Red Hat Developer Toolset (RHDTS), latest dynamic languages, and open source databases from the DevTools repository. Instructions are provided for both the command line (CLI) and graphical user interface (GUI).

Using the Red Hat Subscription Manager GUI

Red Hat Subscription Manager can be started from the System Tools group of the Applications menu. Alternatively, you can start it from the command prompt by typing subscription-manager-gui.

1. On the Subscription Manager System menu, select Repositories.

2. In the list of repositories, check the Enabled column for rhel-server-rhscl-6-rpms and rhel-6-server-optional-rpms. If you are using a workstation version of Red Hat Enterprise Linux, the repositories will be named rhel-workstation-rhscl-6-rpms and rhel-6-workstation-optional-rpms. Note: After clicking, it might take several seconds for the check mark to appear in the enabled column.

If you don’t see any RHSCL repositories in the list, your subscription might not include it. 

See Troubleshooting and FAQ for more information.

Using subscription-manager from the command line

You can add or remove software repositories from the command line using the subscription-manager tool as the root user. Use the --list option to view the available software repositories and verify that you have access to RHSCL, which includes RHDTS:

$ su -
# subscription-manager repos --list | egrep rhscl

If you don’t see any RHSCL repositories in the list, your subscription might not include it. See Troubleshooting and FAQ for more information.

If you are using a desktop edition of RHEL, change -server- to -desktop- in the following commands:

# subscription-manager repos --enable rhel-server-devtools-6-rpms
# subscription-manager repos --enable rhel-6-server-optional-rpms

Install GCC tool chain from the command line

In this next step you will use a single command to download and install GCC 7, and other development tools that are part of Red Hat Developer Toolset. The length of time this step takes depends on the speed of your Internet connection and your system. With a reasonably fast connection, this step should complete in well under 5 minutes.

$ su -
# yum install devtoolset-7

If you want to install a subset of components, see the instructions here.

Note: You will still use devtoolset-7 as the name of the software collection in all scl commands. Only the name of the meta-package to be installed by yum changes.

Using DTS C++ from the command line without an IDE

The GNU C++ compiler is run with the command, g++. You need to add DTS to your environment with scl enable in a Terminal window. Also see Permanently adding DTS to your Development Environment for more information.

$ scl enable devtoolset-7 bash

Now create hello.cpp using a text editor such as vi, nano, or gedit with the following content:

hello.cpp

#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {
  cout << "Hello, Red Hat Developer Program World!" << endl;
  return 0;
}

Now compile and run the program:

$ g++ -o hello hello.cpp
$ ./hello
Hello, Red Hat Developer Program World!

For more information, see the GNU C++ Compiler section of the Red Hat Developer Toolset 7 User Guide.

Docker-formatted container images

Docker-formatted container images can be used to run Red Hat Developer Toolset components inside virtual software containers, thus isolating them from the host system and allowing for their rapid deployment. For detailed description of the Red Hat Developer Toolset docker-formatted container images and Red Hat Developer Toolset dockerfiles, see Using Red Hat Software Collections Container Images.

Working with the Red Hat Developer Toolset and Software Collection packages

The Red Hat Developer Toolset is delivered as a set of packages in the Red Hat Software Collection. The software packages in RHSCL are designed to allow multiple versions of software to be installed concurrently. To accomplish this, the desired package is added to your runtime environment as needed with the scl enable command. When scl enable runs, it modifies environment variables and then runs the specified command. The environmental changes only affect the command that is run by scl and any processes that are run from that command. The steps in this tutorial run the command bash to start a new interactive shell to work in the updated environment. The changes aren’t permanent. Typing exit will return to the original shell with the original environment. Each time you login, or start a new terminal session, scl enable needs to be run again.

While it is possible to change the system profile to make RHSCL packages part of the system’s global environment, this is not recommended. Doing this can cause conflicts and unexpected problems with other applications because the system version of the package is obscured by having the RHSCL version in the path first.

Permanently adding DTS to your development environment

To make DTS a permanent part of your development environment, you can add it to the login script for your specific user ID. This is the recommend approach for development, because only processes run under your user ID will be affected.

Using your preferred text editor, add the following line to the end of ~/.bashrc:

source scl_source enable devtoolset-7

After logging out and logging back in again, you can verify that the DTS GCC is in your path by running which g++ or g++ -v.

$ which g++
/opt/rh/devtoolset-7/root/usr/bin/g++

$ g++ -v
g++ (GCC) 7.2.1 20170729 (Red Hat 7.2.1-1)