Date: Fri, 27 Nov 1998 10:14:17 +0100 (MET) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: hackers@FreeBSD.ORG Subject: 64 char limit for #!/ command interpreters ? Message-ID: <199811270914.KAA11281@labinfo.iet.unipi.it>
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Hi, I use to put in my MagicPoint presentations a first line of the form #!/usr/local/bin/mgp ...bla bla bla... so that the interpreter is invoked automatically on the presentation file. Not without surprise, i just noticed that the process fails if the first line is longer than 64 characters (this is on 2.2.6). The limit is apparently in /sys/kern/imgact_shell.c: #define MAXSHELLCMDLEN 64 Now, any idea why the limit is so small, and is there any danger to raise it to a much larger value such as 256 or so ? The reason i am asking is because this mechanism becomes more useful as the number of parameters increases... (and i happen to have hit the limit!) I think i know why the limit is there -- to avoid that some arbitrary binary file can be mistaken for a shell script with an interpreter name if an newline is not found "soon". Still, as we can have a pathname up to 1KB (PATH_MAX in syslimits.h) the 64byte constraint seems a bit inconsistent... luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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