On Sun, Oct 31, 2021 at 08:36:49PM +0300, Oğuz wrote: > On Sun, Oct 31, 2021 at 7:07 PM Mike Jonkmans <bash...@jonkmans.nl> wrote: > > > > On Sun, Oct 31, 2021 at 05:23:03PM +0200, Oğuz wrote: > > > 31 Ekim 2021 Pazar tarihinde Mike Jonkmans <bash...@jonkmans.nl> yazdı: > > > > > > > > Using the hash as alias for commands, that are not in your PATH, > > > > seems risky though. > > > > > > Why? Risky how? > > > > Risky, mostly on a cognitive level. > > > > 'command -p foo' doesn't look like it has a side effect. > > How does a command look like it has side effects?
Changing PATH would be well known to have side effects. Also, i wouldn't be surprised of '/bin/rm -rf /bin' influencing things. > > E.g. assume you have /usr/local/bin/foo and /bin/foo > > PATH=/usr/local/bin > > command -p foo > > foo > > > > You would not think that /bin/foo is executed for foo, given the value of > > PATH. > > I suppose I would not, because the manual doesn't say `command -p' has > this effect. I'll give you that. POSIX is also silent on this. > > It could also lead to bugs. > > E.g. > > PATH=/usr/local/bin > > source script > > foo > > > > When the 'command -p foo' is introduced in the sourced script, foo changes. > > Yes, that's how `source' works; contents of the sourced file alters > the sourcing application's execution environment. In addition to > calling `command -p foo', if the sourced file changes `PATH', or > defines a function named `foo', or enables `expand_aliases' and > defines an alias named `foo', `foo' 'changes'. Note that it is not always the same person writing the code. The script might be written/changed by someone unaware of the side effects. I assume script writers would know about PATH and alias effects, less so about 'hash' and even fewer people would know about 'command -p'. -- Regards, Mike Jonkmans
