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Top Forums Shell Programming and Scripting Shell quoting rules for other languages programmers Post 302717711 by Corona688 on Thursday 18th of October 2012 01:06:01 PM
Old 10-18-2012
Yes, I know what you mean. I remember when I was starting with Linux, I didn't understand shell very well, and tried to write most of everything in Perl. This didn't make bash stupid, or eval necessary, I simply didn't know what I was doing.

Quote:
But seriously using eval cannot be so harmful...It's just re-evaluation of strings.
Yes. Yes, it can.

Imagine that you're feeding variables containing filenames into eval. Did you know that `rm -Rf ~/` is a valid filename?

Using eval lets external things inject whatever code they want into your program unless done very very carefully. If you don't know enough to avoid eval, you probably don't know how to use it safely either.

Last edited by Corona688; 10-18-2012 at 02:15 PM..
 

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ExtUtils::MM_Win32(3pm) 				 Perl Programmers Reference Guide				   ExtUtils::MM_Win32(3pm)

NAME
ExtUtils::MM_Win32 - methods to override UN*X behaviour in ExtUtils::MakeMaker SYNOPSIS
use ExtUtils::MM_Win32; # Done internally by ExtUtils::MakeMaker if needed DESCRIPTION
See ExtUtils::MM_Unix for a documentation of the methods provided there. This package overrides the implementation of these methods, not the semantics. constants (o) Initializes lots of constants and .SUFFIXES and .PHONY static_lib (o) Defines how to produce the *.a (or equivalent) files. dynamic_bs (o) Defines targets for bootstrap files. dynamic_lib (o) Defines how to produce the *.so (or equivalent) files. perl_script Takes one argument, a file name, and returns the file name, if the argument is likely to be a perl script. On MM_Unix this is true for any ordinary, readable file. pm_to_blib Defines target that copies all files in the hash PM to their destination and autosplits them. See "DESCRIPTION" in ExtUtils::Install tool_autosplit (override) Use Win32 quoting on command line. tools_other (o) Win32 overrides. Defines SHELL, LD, TOUCH, CP, MV, RM_F, RM_RF, CHMOD, UMASK_NULL in the Makefile. Also defines the perl programs MKPATH, WARN_IF_OLD_PACKLIST, MOD_INSTALL. DOC_INSTALL, and UNINSTALL. xs_o (o) Defines suffix rules to go from XS to object files directly. This is only intended for broken make implementations. top_targets (o) Defines the targets all, subdirs, config, and O_FILES manifypods (o) We don't want manpage process. dist_ci (o) Same as MM_Unix version (changes command-line quoting). dist_core (o) Same as MM_Unix version (changes command-line quoting). pasthru (o) Defines the string that is passed to recursive make calls in subdirectories. perl v5.8.0 2002-06-01 ExtUtils::MM_Win32(3pm)
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