Try this to get the concept...
Output
It will shift the arguments from right to left
Lets say, you have 3 arguments i.e. $1=a, $2=b, $3=c
Now you "shift" and try priting $1, it will print "b" and $2 will be "c" and there will no $3
There is an error when i am trying to use the shift command in this way:
($1 = -d, $2 = 123, $3 = -c etc etc)
for $arg in $@
do
case $arg in
"-d") shift; (so that the $2 will become the $arg now)
(and while it loop the 2nd time,)
... (1 Reply)
hi all, when I press SHIFT at once it work like as
I've hold it (like CapsLock is On, but it Off) ! ... and if I press F1 (or another
function key) it put out 24z :(
it is occure on my remote sun 8 , xterm session
help me please ! (2 Replies)
Hi Folks,
In shell scripting the maximum no. of command line parameters becomes 9(Am i right). If we want to get more than 9 parameters we use the shift command.
Even here there are two possibilities.
1. Without the use of variables - The arguments are lost and the lost no. is equal to the... (6 Replies)
I am running a program where in I have this command
which is giving error the shift: number is not correct.
can you please tell me how shift actually works?
the line which is giving error is-
set $PARAM; shift; shift; shift; shift; shift; shift; shift; shift
Is it related somewhere to... (2 Replies)
Hi,
I wrote one script, in between script needs to use 10th and 11th positional parameters, that time i used "shift". Here i am facing the below find problem,
./DataCount.sh: cannot shift
I tried
1) I have read man pages for shift
2) Before but * and **
3) Simple shift with out giving... (4 Replies)
I would need the awk command or a better way to get my file that looks like
1234
5678
8912
3456
7890
to look like
1234,5678,8912,3456,7890
Thanks in advance (4 Replies)
Hi,
Firstly, I did a search for this question both on this site and on the internet and have not been able to find a suitable answer that is not general in nature.
I have always been a Windows user. I use my girl friend's mac every now and then, but I always come back to windows. For a... (1 Reply)
think using shift would help me finish my script but cant get it work without your help. would appreciate if you give me a example with shift & counter in the same script so I can later work on that to my one.
Thanks and Good Luck! (1 Reply)
Hello,
I am reading one of the AIX manuals about shell scripting and (AIX 5) and I found this example when introducing to functions:
function usage
{
prog="$1"; shift
print -u2 "$prog: usage: $prog $@"
exit 1
}
This example is meant to be easy but I don't understand what it is... (5 Replies)
#!/bin/bash
hostname=$1; shift
for hostname in $1
do
ping $hostname
done
I want to run the above script as hostname.sh yahoo.com google.com cnn.com. I want to shift each hostname to $1. How can do that with above code as currently it's not shifting. (5 Replies)
Discussion started by: scj2012
5 Replies
LEARN ABOUT OSX
getopt
GETOPT(1) BSD General Commands Manual GETOPT(1)NAME
getopt -- parse command options
SYNOPSIS
args=`getopt optstring $*` ; errcode=$?; set -- $args
DESCRIPTION
The getopt utility is used to break up options in command lines for easy parsing by shell procedures, and to check for legal options.
Optstring is a string of recognized option letters (see getopt(3)); if a letter is followed by a colon, the option is expected to have an
argument which may or may not be separated from it by white space. The special option '--' is used to delimit the end of the options. The
getopt utility will place '--' in the arguments at the end of the options, or recognize it if used explicitly. The shell arguments ($1 $2
...) are reset so that each option is preceded by a '-' and in its own shell argument; each option argument is also in its own shell argu-
ment.
EXAMPLES
The following code fragment shows how one might process the arguments for a command that can take the options -a and -b, and the option -o,
which requires an argument.
args=`getopt abo: $*`
# you should not use `getopt abo: "$@"` since that would parse
# the arguments differently from what the set command below does.
if [ $? != 0 ]
then
echo 'Usage: ...'
exit 2
fi
set -- $args
# You cannot use the set command with a backquoted getopt directly,
# since the exit code from getopt would be shadowed by those of set,
# which is zero by definition.
for i
do
case "$i"
in
-a|-b)
echo flag $i set; sflags="${i#-}$sflags";
shift;;
-o)
echo oarg is "'"$2"'"; oarg="$2"; shift;
shift;;
--)
shift; break;;
esac
done
echo single-char flags: "'"$sflags"'"
echo oarg is "'"$oarg"'"
This code will accept any of the following as equivalent:
cmd -aoarg file file
cmd -a -o arg file file
cmd -oarg -a file file
cmd -a -oarg -- file file
SEE ALSO sh(1), getopt(3)DIAGNOSTICS
The getopt utility prints an error message on the standard error output and exits with status > 0 when it encounters an option letter not
included in optstring.
HISTORY
Written by Henry Spencer, working from a Bell Labs manual page. Behavior believed identical to the Bell version. Example changed in FreeBSD
version 3.2 and 4.0.
BUGS
Whatever getopt(3) has.
Arguments containing white space or embedded shell metacharacters generally will not survive intact; this looks easy to fix but isn't. Peo-
ple trying to fix getopt or the example in this manpage should check the history of this file in FreeBSD.
The error message for an invalid option is identified as coming from getopt rather than from the shell procedure containing the invocation of
getopt; this again is hard to fix.
The precise best way to use the set command to set the arguments without disrupting the value(s) of shell options varies from one shell ver-
sion to another.
Each shellscript has to carry complex code to parse arguments halfway correcty (like the example presented here). A better getopt-like tool
would move much of the complexity into the tool and keep the client shell scripts simpler.
BSD April 3, 1999 BSD