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Full Discussion: BASH Environment Variables as arguments?
Homework and Emergencies Homework & Coursework Questions BASH Environment Variables as arguments? Post 302393733 by Helix on Tuesday 9th of February 2010 12:12:28 PM
Old 02-09-2010
BASH Environment Variables as arguments?
1. The problem statement, all variables and given/known data:
Write a shell program called myenv which takes one argument. The argument should be the name of an environment variable, such as PATH HOME etc. myenv should print out the value of the variable given as the argument. If no argument is given, or the argument is invalid, your program could do unpredictable things!
e.g., myenv PRINTER
should print a line such as: PRINTER=kc3500
e.g., myenv HOME PRINTER
should print a line such as: HOME=/home/dwoit


2. Relevant commands, code, scripts, algorithms:
None that I can think of? Besides the basic start of #!/bin/bash


3. The attempts at a solution (include all code and scripts):
I'm not sure how to write this... I assume I could try setting the argument to a local variable within the script, but that's the next topic (local variables) so I don't think I have to. I know you can see the values of environment variables by typing in $ and then the one you want, so I tried doing ${"$1"} within the program but it doesn't work (I get a bad substitution error) and I have no idea how else to do it. Any help is appreciated, thanks.

#!/bin/bash
echo ${"$1"}
exit 0

4. Complete Name of School (University), City (State), Country, Name of Professor, and Course Number (Link to Course):
Ryerson University, Toronto, Canada, Denise Woit, CPS393
 

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LEARN ABOUT OPENSOLARIS

telnetrc

telnetrc(4)							   File Formats 						       telnetrc(4)

NAME

       telnetrc - file for telnet default options

DESCRIPTION

       The   .telnetrc	file  contains commands that are executed when a connection is established on a per-host basis. Each line in the file con-
       tains a host name, one or more spaces or tabs, and a telnet(1) command. The host name, DEFAULT, matches all hosts. Lines beginning with the
       pound  sign (#) are interpreted as comments and therefore ignored. telnet(1) commands are case-insensitive to the contents of the .telnetrc
       file.

       The  .telnetrc file is retrieved from each user's  HOME directory.

EXAMPLES

       Example 1: A sample file.

       In the following example, a .telnetrc file executes the telnet(1) command, toggle:

       weirdhost toggle crmod
       # Always export $PRINTER
       DEFAULT environ export PRINTER

       The lines in this file indicate that the toggle argument crmod, whose default value is "off" (or FALSE), should be enabled when	connecting
       to  the	system weirdhost. In addition, the value of the environment variable  PRINTER should be exported to all systems. In this case, the
       DEFAULT keyword is used in place of the host name.

FILES

       $HOME/.telnetrc

SEE ALSO

       telnet(1), in.telnetd(1M), environ(5)

SunOS 5.10							    9 Jan 1998							       telnetrc(4)
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