envdir — set environment variables then chain
envdir [--ignore-nodir] [--full] [--chomp] {dir} {next-prog}
envdir is a chain-loading utility that sets and unsets environment variables according to the files in dir and then chain loads to next-prog with the execvp(3) function.
next-prog may contain its own command line options, which envdir will ignore.
Unless the [--ignore-nodir] command line option is used, the non-existence of dir, or it being something other than a directory, is a fatal error.
For each file file in dir:
If the file is empty, envdir unsets the variable file if it is set.
Otherwise envdir sets the variable file, overwriting its existing value if it has one, to the contents of file, after turning NUL characters into LF characters (and turning the final LF character into a string-terminating NUL).
If the [--full] command line option is used, envdir uses the full contents of file; otherwise it uses just the first line of those contents.
This is a bodge for malformed out-of-spec environment directories.
Always create environment directories properly, according to the Bernstein specification, and you should never need this.
Use tr(1) in shell scripts to properly translate LFs to NULs for writing environment directories, for example.
If the [--chomp] command line option is used, each line used has leading and trailing whitespace characters trimmed.
envdir skips directory entries that aren't regular files (or symbolic links to regular files), trying not to even attempt to open them if the operating system's directory scanning ability includes the reporting of entry types. It also skips entries whose names begin with a dot.
envdir makes no attempt to sanitize the contents of file or the name file.
If the name or the contents contain an = character, counter-intuitive things will happen to the environment.
If the contents have whitespace at the end of the first line, that will be included in the variable's value in the environment.
As of version 1.34 this program no longer employs the GNU C library nor the BSD C library for environment variable handling. The previously documented workaround for those libraries' having memory leaks in their setenv(3) and clearenv(3) functions, is therefore no longer necessary.