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Top Forums Shell Programming and Scripting shell programming if statement help Post 302604214 by agama on Saturday 3rd of March 2012 07:42:26 PM
Old 03-03-2012
If "boy" is entered it will never equal 'a' or 'b' and so the expression will always evaluate to false.

Since you are using kshell, the right hand side of an expression in double brackets is treated as a pattern and you can code:

Code:
[[ $word == "b"* ]]

to test if the expansion of $word is a 'b' followed by zero or more characters.

The asterisk (*) must be outside of the quotes or shell will not treat it as a meta character.

If you must, or would rather, use single brackets, then you can code something like this:

Code:
[ "${word:0:1}" -eq "b" ]

Which will take the first character of the value of word and compare it to 'b.' If you try to use pattern characters inside of single brackets the shell will treat them as filename globbing characters and you'll end of with undesired results.
 

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newgrp(1)						      General Commands Manual							 newgrp(1)

NAME
newgrp - change effective group ID sg - execute command with different group ID SYNOPSIS
newgrp [-l] [group] sg group -c command DESCRIPTION
The newgrp command changes the user's real and effetive group ID by replacing the current shell with a new shell. A new shell is launched even if an error occours. A password is requested if the group has a password and the user is not listed in the group file as being a member of that group. The pass- word can be changed with the gpasswd(1) command. If the new effective group ID is not in the supplementary group list, newgrp will add the new group ID to the supplementary list, too. With no operands and options, newgrp changes the user's group IDs (real and effective) back to the group specified in password and group file. The sg command works like the newgrp command, except that it executes the given command with /bin/sh and upon exit the group ID of the cur- rent shell is not changed. OPTIONS
-l, --login reinitialize the environment as if the user logged in. --help Print a help list. -u, --usage Print a short usage message. -v, --version Print program version. SEE ALSO
gpasswd(1), group(5), passwd(1), passwd(5), su(1) AUTHOR
Thorsten Kukuk <kukuk@suse.de> pwdutils April 2004 newgrp(1)
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