Re: [PATCH] Linux 2.6: shebang handling in fs/binfmt_script.c

From: Paul Jackson (pj_at_sgi.com)
Date: 02/23/04

  • Next message: David S. Miller: "Re: Intel vs AMD x86-64" 
    Date:	Mon, 23 Feb 2004 13:46:10 -0800
To: Andries Brouwer <aebr@win.tue.nl>

    Andries Brouwer wrote:
    > If there is such nonblank text then for SysVR4,
    > SunOS, Solaris, IRIX, HPUX, AIX, Unixware, Linux, OpenBSD, Tru64
    > this group consists of precisely one argument.
    > FreeBSD, BSD/OS, BSDI split the text

    Interesting - I notice that 9 Operating Systems, in addition to Linux,
    don't split the optional shebang argument, and 3 do.

    All else equal, I am not enthusiastic about a somewhat arbitrary change
    that could be done either way, that is actually done more often in other
    operating systems the current way, and that potentially affects both
    script files and their interpreters (shells, awk, perl, python, guile,
    tcl, bc, ...).

    I will acknowledge however that if there was a shell or interpreter that
    allowed at most one '-' prefixed option before the path to the script
    file to be interpreted, that that shell or interpreter would be poorly
    coded.

    And, to be truthful, the usual way that I code awk scripts is not as
    a shbang script with an interpreter of awk,

      #!/bin/awk
      BEGIN ...

    but rather as a quoted awk script within a shell script:

      #!/bin/sh
      awk '
        BEGIN ...
      '

    It is then trivial to supply one or several options to 'awk', and
    (as the tclsh man page notes) to cope with possible diverse locations
    along $PATH of the interpreter.

    This is especially useful in the case of awk, since it is not a
    convenient language for many things that are easily done in a shell.
    That is, I don't write awk scripts, so much as I write shell scripts
    that might make use of awk.

    This is a portable habit, that avoids all the afore mentioned
    limitations and inconsistencies in shbang handling. 

    -- 
                          I won't rest till it's the best ...
                          Programmer, Linux Scalability
                          Paul Jackson <pj@sgi.com> 1.650.933.1373
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