What is the meaning the $ special character? Post: 303006544

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Top Forums UNIX for Beginners Questions & Answers What is the meaning the $ special character? Post 303006544 by bakunin on Friday 3rd of November 2017 09:26:48 AM

11-03-2017

Registered User

Also note that there are some special variables which are also introduced by "$":

$$ = process number of the currently running process
$* = all the arguments passed to a process (or subfunction of a script)
$@ = same as above*)
$# = number of all the arguments passed to a process (or subfunction of a script)
$! = process number of the background process invoked by the current process
$? = the return code of the last process executed
$1 ($2, $3, ...) = the first (second, third, ...) positional parameter passed to that process

I hope this helps.

bakunin
____________
*) "$*" and "$@" are basically the same, except when quoted. "$*" gives all arguments surrounded by spaces, "$@" gives all arguments surrounded by quotes. For instance, you call a script this way:

Code:

myscript.sh "one arg" "two arg" "three arg"

Inside the script you use "$*" and you get a single string: "one arg two arg three arg", whereas when you use "$@" you get three strings: "one arg" "two arg" "three arg".

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LEARN ABOUT DEBIAN

ns_socksetnonblocking

Ns_Sock(3aolserver)					   AOLserver Library Procedures 				       Ns_Sock(3aolserver)

__________________________________________________________________________________________________________________________________________________

NAME

       Ns_BindSock,  Ns_GetSockAddr,  Ns_SockAccept,  Ns_SockAsyncConnect,  Ns_SockAsyncConnect2,  Ns_SockBind, Ns_SockCloseLater, Ns_SockConnect,
       Ns_SockConnect2, Ns_SockListen, Ns_SockListenEx, Ns_SockPipe, Ns_SockSetBlocking, Ns_SockSetNonBlocking, Ns_SockStrError,  Ns_SockTimedCon-
       nect, Ns_SockTimedConnect2, ns_pipe, ns_sockpair - library procedures

SYNOPSIS

       #include "ns.h"

       Ns_BindSock(arg, arg)

       Ns_GetSockAddr(arg, arg)

       Ns_SockAccept(arg, arg)

       Ns_SockAsyncConnect(arg, arg)

       Ns_SockAsyncConnect2(arg, arg)

       Ns_SockBind(arg, arg)

       Ns_SockCloseLater(arg, arg)

       Ns_SockConnect(arg, arg)

       Ns_SockConnect2(arg, arg)

       Ns_SockListen(arg, arg)

       Ns_SockListenEx(arg, arg)

       Ns_SockPipe(arg, arg)

       Ns_SockSetBlocking(arg, arg)

       Ns_SockSetNonBlocking(arg, arg)

       Ns_SockStrError(arg, arg)

       Ns_SockTimedConnect(arg, arg)

       Ns_SockTimedConnect2(arg, arg)

       ns_pipe(arg, arg)

       ns_sockpair(arg, arg)
_________________________________________________________________

DESCRIPTION

       These functions ...

SEE ALSO

       nsd(1), info(n)

KEYWORDS

AOLserver								4.0						       Ns_Sock(3aolserver)

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