execline: the posix-cd command
Keywords: execline command cd chdir posix posix-cd

execline
Software
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# The `posix-cd` program

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

## Interface

         posix-cd [ -L | -P ] dir prog...

`posix-cd` changes the current working directory to dir according to the POSIX specification for a `cd` external utility. Then, if prog... is not empty, it execs into it.

## Notes

- When execline has been configured with the `--enable-pedantic-posix` option, the `cd` command is a symbolic link to it. So scripts calling `cd` will use `posix-cd`. When this configuration option has not been given, `cd` is a symbolic link to execline-cd.
- `posix-cd` fully conforms to the POSIX specification. When prog... is not empty, the behaviour of a `cd` utility is not specified by POSIX, so `posix-cd` extends the spec to be actually useful and usable in an execline program with the same interface as the regular execline cd command.
- Nobody ever executes or needs the external version (i.e. not a shell builtin) of the POSIX `cd` command. Compared to execline's regular `cd` binary, execline-cd, `posix-cd` is uselessly bloated and slow. The only reason it exists is that some distributions refuse to package execline correctly unless it is strictly POSIX-compliant; the `--enable-pedantic-posix` configure option is there to satisfy their requirements.