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Full Discussion: Is it possible in a shell script to modify itself ??
Top Forums Shell Programming and Scripting Is it possible in a shell script to modify itself ?? Post 67377 by TioTony on Tuesday 22nd of March 2005 10:40:31 PM
Old 03-22-2005
I have done something similar in a college AI class where we looked at the efficiency of different languages for AI. I wrote a script that replaced the file it was run from with new code, then ran the new script. Once the scirpt is running you can blow away it's file on disk since it is running from a copy in memory. I think you could pursue two methods to get the results you want.

1. In the script create a procedure that contains the entire text of the script itself and echo's it to $0 (this is the name of the file that was run in the first place). Then just run the procedure and have another section of code spit the new answers into the file as well.

2. Use a unique comment on the end of the lines containing the answers. Use sed to add/remove/modify lines in this section with the new answers from within the script.

This will work but using an external text file is probably a better way to go.
 

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LEARN ABOUT DEBIAN

platform::shell

platform::shell(3tcl)					       Tcl Bundled Packages					     platform::shell(3tcl)

__________________________________________________________________________________________________________________________________________________

NAME

       platform::shell - System identification support code and utilities

SYNOPSIS

       package require platform::shell ?1.1.4?

       platform::shell::generic shell
       platform::shell::identify shell
       platform::shell::platform shell
_________________________________________________________________

DESCRIPTION

       The platform::shell package provides several utility commands useful for the identification of the architecture of a specific Tcl shell.

       This  package  allows the identification of the architecture of a specific Tcl shell different from the shell running the package. The only
       requirement is that the other shell (identified by its path), is actually executable on the current machine.

       While for most platform this means that the architecture of the interrogated shell is identical to the architecture of  the  running  shell
       this  is  not generally true. A counter example are all platforms which have 32 and 64 bit variants and where a 64bit system is able to run
       32bit code. For these running and interrogated shell may have different 32/64 bit settings and thus different identifiers.

       For applications like a code repository it is important to identify the architecture of the shell which will  actually  run  the  installed
       packages, versus the architecture of the shell running the repository software.

COMMANDS

       platform::shell::identify shell
	      This command does the same identification as platform::identify, for the specified Tcl shell, in contrast to the running shell.

       platform::shell::generic shell
	      This command does the same identification as platform::generic, for the specified Tcl shell, in contrast to the running shell.

       platform::shell::platform shell
	      This command returns the contents of tcl_platform(platform) for the specified Tcl shell.

KEYWORDS

       operating system, cpu architecture, platform, architecture

platform::shell 						       1.1.4						     platform::shell(3tcl)
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