On Tue, 28 Mar 2017 16:43:17 -0400 Chet Ramey <chet.ra...@case.edu> wrote: > > On 3/28/17 12:43 PM, Torka Noda wrote: > > > Actually, shouldn't `bash -s`, without any command fed to > > its stdin, exit immediately, anyway...? > > No. Why? It reads and executes commands from its standard > input, which is in most cases, the terminal. However, `bash > -s foo </dev/null' should exit immediately. >
... Because I misread the manual, forgot the "when invoking an interactive shell" part, and didn't do enough tests to compensate :) I thought the following command would print "foo bar", as in "it would set the positional parameters (as in 'arguments') for the commands themselves, fed to Bash's stdin on start": ======================================== $ echo 'echo' | bash -s foo bar $ ======================================== Instead it prints nothing, and only sets Bash's positional parameters, so I could use the following command to get that result: ======================================== $ echo 'echo $1 $2' | bash -s foo bar foo bar $ ======================================== The same goes for `bash -c`: ======================================== $ bash -c 'echo' foo bar $ bash -c 'echo $0 $1 $2' bash foo bar bash foo bar ======================================== I now understand better what Daniel Mills was saying... ... except that `echo 'echo $1 $2' | bash -s foo bar` would not read ~/.bashrc, because in this case the shell is not interactive, so no possible modification of the positional parameters specified on the command-line, unless the shell is fully interactive, in which case we can already use `set -- foo bar` whenever we want, including from initialization files... ... and I'm not sure that, philosophically, command-line arguments are supposed to keep the priority, over active initialization files (compared to plain configuration files, which should indeed be overridden by the command-line). And they currently don't, anyway. So, in the end, we can set Bash's positional parameters from ~/.bashrc, and use them then, and they'll override the command-line specified ones in interactive shells, but we can never access the original ones from ~/.bashrc... Also, `bash -s foo bar` is actually the proper way to do what I want, then... It *is* supposed to set Bash's positional parameters, not the ones of the commands fed to its stdin... The only problem is that they are not accessible from initialization files... Well, sorry for the confusion, I'll stop here. I think it's weird for Bash's positional parameters, and the whole argument list if modified with '-s', not to be accessible from initialization files, but `env` does what I want relatively simply compared to the tricks used by other people on the web, and I'll be content with that.
