Re: PATH vs current dir and dir sure to be not existing
| Newsgroups | gmane.os.netbsd.devel.userlevel |
|---|---|
| Message-ID | <[email protected]> |
On Sat, Sep 28, 2024 at 06:24:58PM +0700, Robert Elz wrote: > Date: Sat, 28 Sep 2024 10:33:55 +0200 > From: <[email protected]> > Message-ID: <[email protected]> > > | This does mean that one user setting a PATH with variables: > | > | PATH="/bin:/usr/bin:$MYSCRIPTS:/usr/pkg/bin" > | > | if MYSCRIPTS is not defined, will end up including the current working > | dir in his PATH, while it was not the intention. > > Yes. The expansion happens before the value is assigned to > the variable. There is no difference between that and explicitly > including :: > > | The general rule of safety is doing: > | PATH="/bin:/usr/bin:${MYSCRIPTS:-/not/existing}:/usr/pkg/bin" > > You could, but that would be wasteful. > > Better would be: > > PATH="/bin:/usr/bin:${MYSCRIPTS:+${MYSCRIPTS}:}/usr/pkg/bin" > or > PATH="/bin:/usr/bin${MYSCRIPTS:+:${MYSCRIPTS}}:/usr/pkg/bin" > > whichever you prefer (they are essentially the same thing). > > Why stick an entry in PATH that you intend not to be used? Since I'm writing a pathsearch.7 to explain the PATH_SEARCH_OPT option(s) for "qualified filenames" (searching in PATH for "dk/ctl", "vect/in/dxf" etc.), Il will add your suggestion of expanding with a colon only if defined. Neat. Best, -- Thierry Laronde <tlaronde +AT+ kergis +dot+ com> http://www.kergis.com/ http://kertex.kergis.com/ Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C