The `execline-cd` program

execline-cd changes the current working directory to a given directory, then executes a program.

Interface

     execline-cd dir prog...

execline-cd performs a chdir() system call on dir, then execs into prog....

By default, execline-cd can also be invoked as cd: there is a cd program which is a symbolic link to execline-cd.
When execline has been configured with the --enable-pedantic-posix option, the cd binary is a symbolic link to the posix-cd binary instead, so a cd command in an execline script will invoke posix-cd instead of execline-cd.
Existing scripts that call cd will keep working no matter the chosen configuration.