Sponsored Content
Full Discussion: Use of Shift command
Top Forums Shell Programming and Scripting Use of Shift command Post 302570300 by ahamed101 on Thursday 3rd of November 2011 01:52:14 AM
Old 11-03-2011
Try this to get the concept...
Code:
[root@bt] $ cat run
#!/bin/bash

set -- "1" "2" "3" "4" "5"
echo $*
shift
echo $*
shift
echo $*
shift
echo $*

Output
Code:
[root@bt] $ ./run
1 2 3 4 5
2 3 4 5
3 4 5
4 5

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

HTH
--ahamed
This User Gave Thanks to ahamed101 For This Post:
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

shift command

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)
Discussion started by: AkumaTay
1 Replies

2. UNIX for Dummies Questions & Answers

xterm SHIFT crazy

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)
Discussion started by: oneivan
2 Replies

3. Shell Programming and Scripting

shift command

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)
Discussion started by: Nisha
6 Replies

4. Shell Programming and Scripting

Regarding the shift command???

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)
Discussion started by: shrao
2 Replies

5. UNIX for Dummies Questions & Answers

shift not working

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)
Discussion started by: Nagapandi
4 Replies

6. Shell Programming and Scripting

AIX command to shift up

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)
Discussion started by: bombcan
4 Replies

7. UNIX for Dummies Questions & Answers

A Shift into UNIX

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)
Discussion started by: mearex
1 Replies

8. UNIX for Dummies Questions & Answers

can someone explain shift command in script?

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)
Discussion started by: me.
1 Replies

9. Shell Programming and Scripting

AIX function example with "shift" command

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)
Discussion started by: Kibou
5 Replies

10. Shell Programming and Scripting

Shift command help

#!/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
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
All times are GMT -4. The time now is 01:46 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy