To export a shell variable in the C shell (csh) or the TENEX C shell (tcsh) on a FreeBSD system, you can use the setenv command.
The setenv command sets an environment variable to a specified value and exports it to the environment of all child processes.
To set and export a shell variable using setenv, you can use the following syntax:
setenv VARNAME value
Replace VARNAME with the name of the shell variable, and value with the value you want to set for the variable.
For example, to set and export the PATH variable to /usr/local/bin:/usr/bin:/bin, you can use the following command:
setenv PATH /usr/local/bin:/usr/bin:/bin
To display the value of an exported shell variable, you can use the echo command, followed by the name of the variable preceded by a $ symbol. For example:
echo $PATH
This will display the value of the PATH variable.
For more information about using the setenv command and exporting shell variables in the C shell and TENEX C shell, you can refer to the csh and tcsh man pages by running man csh and man tcsh on the command line.