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From: u-uy74@aetey.se
To: musl@lists.openwall.com
Subject: Re: Question about setting argv[0] when manually using dynamic linker
Date: Wed, 17 May 2017 11:01:03 +0200	[thread overview]
Message-ID: <20170517070115.GL6320@example.net> (raw)
In-Reply-To: <CACBMf30_2GBzDxnLyKzm7MUJZu7-xy-SNw5eBT=xDiC-N+PQOw@mail.gmail.com>

On Tue, May 16, 2017 at 08:38:56PM -0400, John Regan wrote:
> Hi there - I was wondering if it's possible to somehow set argv[0] when
> calling the dynamic linker to load a program.
 ...
> I'd like to retain whatever was actually typed on the command line (in this
> case, set argv[0] to "app"), since many apps look at argv[0] to change
> behavior, ie - gzip vs gunzip.
> 
> I tried seeing if there was some switch I could pass to the linker, etc -
> as far as I can tell, there's no easy way to do this.

Set argv[0] to whatever you need when you exec*() the dynamic loader,
which is straightforward with a binary wrapper (not with a shell).

A binary wrapper also adds less overhead then going through a shell.

There is imho hardly any incentive to put such functionalty into the
loader. I say this even though we are dependent here on such tricks,
to work around programs which insist on guessing things when not asked to.

Regards,
Rune



  reply	other threads:[~2017-05-17  9:01 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-17  0:38 John Regan
2017-05-17  9:01 ` u-uy74 [this message]
2017-05-17 11:00   ` mzpqnxow
2017-05-17 16:07     ` mzpqnxow
2017-05-17 16:16       ` John Regan
2017-05-17 16:24         ` Rich Felker
2017-05-17 19:07           ` u-uy74
2017-05-17 19:16             ` John Regan
2017-05-17 21:10               ` u-uy74
2017-05-17 21:15               ` mzpqnxow
2017-05-17 21:22                 ` John Regan
2017-07-02 17:36           ` u-uy74
2017-07-04 20:58             ` Rich Felker
2017-07-05  6:01               ` u-uy74
2017-07-09  9:23               ` u-uy74
2017-07-09 12:23                 ` Rich Felker
2017-07-09 14:04                   ` u-uy74

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