Messages in this thread |  | | | From | Mark Rosenstand <> | | Subject | Re: Executable shell scripts | | Date | Sat, 13 May 2006 13:17:13 +0200 (CEST) |
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Arjan van de Ven <arjan@infradead.org> wrote: > On Sat, 2006-05-13 at 13:03 +0200, Mark Rosenstand wrote: > > Arjan van de Ven <arjan@infradead.org> wrote: > > > On Sat, 2006-05-13 at 12:38 +0200, Mark Rosenstand wrote: > > > > Hi, > > > > > > > > Is it in any (reasonable) way possible to make Linux support executable > > > > shell scripts? Perhaps through binfmt_misc? > > > > > > ehhhhhh this is already supposed to work. > > > > It doesn't: > > > > bash-3.00$ cat << EOF > test > > > #!/bin/sh > > > echo "yay, I'm executing!" > > > EOF > > bash-3.00$ chmod 111 test > > bash-3.00$ ./test > > /bin/sh: ./test: Permission denied > > is your script readable as well? 111 is just weird/odd.
No, it's executable. This is what makes executable shell scripts distinct from feeding the file to an interpreter.
From http://www.faqs.org/faqs/unix-faq/faq/part4/section-7.html:
The script is called `executable' because just like a real (binary) executable it starts with a so-called `magic number' indicating the type of the executable. In our case this number is `#!' and the OS takes the rest of the first line as the interpreter for the script, possibly followed by 1 initial option like:
#!/bin/sed -f
Suppose this script is called `foo' and is found in /bin, then if you type:
foo arg1 arg2 arg3
the OS will rearrange things as though you had typed:
/bin/sed -f /bin/foo arg1 arg2 arg3
There is one difference though: if the setuid permission bit for `foo' is set, it will be honored in the first form of the command; if you really type the second form, the OS will honor the permission bits of /bin/sed, which is not setuid, of course. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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