bash question

bash question

[Scott@Charter]

[-- Attachment #1: Type: text/plain, Size: 535 bytes --]

I can't get this bash script to work.  It's suppose to print all odd numbers
from 1 to 10.

#!/usr/bin/bash

LIMIT=10
a=1

while [ "$a" -le $LIMIT ]
do
  if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.
    then
      echo -n "$a "
    fi

echo

let "a+=1"
done
echo; echo
exit 0


Can anyone figure out what I am doing wrong?  Can I also see the same thing
written in Perl?

Thanks for your help.



Scott D. Smallsreed
3030 Chipmunk Dr.
Washoe Valley, NV  89704
775.849.8411 Hm
775.849.8412 Fax
775.722.7773 Cell

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: Scott Smallsreed.vcf --]
[-- Type: text/x-vcard; name="Scott Smallsreed.vcf", Size: 366 bytes --]

BEGIN:VCARD
VERSION:2.1
N:Smallsreed;Scott
FN:Scott Smallsreed
TEL;HOME;VOICE:775-849-8411
TEL;HOME;FAX:775-849-8412
ADR;HOME:;;3030 Chipmunk Dr.;Washoe Valley;Nevada;89704;US
LABEL;HOME;ENCODING=QUOTED-PRINTABLE:3030 Chipmunk Dr.=0D=0AWashoe Valley, Nevada 89704=0D=0AUS
EMAIL;PREF;INTERNET:scott.smallsreed@mindspring.com
REV:20040401T004530Z
END:VCARD

Re: bash question

[Luca Ferrari]

On Thursday 01 April 2004 02:45 Scott@Charter's cat walking on the keyboard  
wrote:

> I can't get this bash script to work.  It's suppose to print all odd
> numbers from 1 to 10.
>
> #!/usr/bin/bash
>
> LIMIT=10
> a=1
>
> while [ "$a" -le $LIMIT ]
> do
>   if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.

This is an awkard way to print all odd numbers, have a look at this:

#!/bin/bash

LIMIT=10
a=1

while test ${a} -lt ${LIMIT}
do
  go=`expr ${a} % 2`
  if test ${go} -ne 0
      then
      echo "Odd number ${a}"
  fi

  a=`expr ${a} + 1`

done


exit 0


In this example, if you change the LIMIT value to 100, the script will print 
you all odds numbers, while in your example you have to put numbers by your 
own. In perl it can result as:

#!/usr/bin/perl

$LIMIT=10;
$a=1;

    while( $a < $LIMIT ){
        if( ($a % 2) !=0 ){
            print "Odd number $a\n";
        }
        $a++;
    }

exit;


Luca


-- 
Luca Ferrari,
fluca1978@virgilio.it

Re: bash question

[Jeff Largent]

And just to show another way:

#!/bin/bash

for i in `seq 1 10`; do
    if [ $((${i} % 2)) != 0 ]; then
       echo ${i}
    fi
done



Luca Ferrari wrote:
> On Thursday 01 April 2004 02:45 Scott@Charter's cat walking on the keyboard  
> wrote:
> 
> 
>>I can't get this bash script to work.  It's suppose to print all odd
>>numbers from 1 to 10.
>>
>>#!/usr/bin/bash
>>
>>LIMIT=10
>>a=1
>>
>>while [ "$a" -le $LIMIT ]
>>do
>>  if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.
> 
> 
> This is an awkard way to print all odd numbers, have a look at this:
> 
> #!/bin/bash
> 
> LIMIT=10
> a=1
> 
> while test ${a} -lt ${LIMIT}
> do
>   go=`expr ${a} % 2`
>   if test ${go} -ne 0
>       then
>       echo "Odd number ${a}"
>   fi
> 
>   a=`expr ${a} + 1`
> 
> done
> 
> 
> exit 0
> 
> 
> In this example, if you change the LIMIT value to 100, the script will print 
> you all odds numbers, while in your example you have to put numbers by your 
> own. In perl it can result as:
> 
> #!/usr/bin/perl
> 
> $LIMIT=10;
> $a=1;
> 
>     while( $a < $LIMIT ){
>         if( ($a % 2) !=0 ){
>             print "Odd number $a\n";
>         }
>         $a++;
>     }
> 
> exit;
> 
> 
> Luca
> 
> 

-- 
Jeff Largent                   ImageLinks, Inc.
Sr System Admin                Melbourne, Fl 32935
(321) 253-0011                 fax: (321) 253-5559

Re: bash question

[Chuck Harding]

How about

#!/bin/bash
for ((i=1;i<11;i+=2))
do
    echo $i
done


man bash shows the usage of the arithmetic for loop which I use all
the time to execute remote commands on systems whose hostnames vary
by an integer node number - e.g., host1, host2, host3, ... host128

On Thu, 1 Apr 2004, Jeff Largent wrote:

> And just to show another way:
>
> #!/bin/bash
>
> for i in `seq 1 10`; do
>     if [ $((${i} % 2)) != 0 ]; then
>        echo ${i}
>     fi
> done
>
>
>
> Luca Ferrari wrote:
> > On Thursday 01 April 2004 02:45 Scott@Charter's cat walking on the keyboard
> > wrote:
> >
> >
> >>I can't get this bash script to work.  It's suppose to print all odd
> >>numbers from 1 to 10.
> >>
> >>#!/usr/bin/bash
> >>
> >>LIMIT=10
> >>a=1
> >>
> >>while [ "$a" -le $LIMIT ]
> >>do
> >>  if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.
> >
> >
> > This is an awkard way to print all odd numbers, have a look at this:
> >
> > #!/bin/bash
> >
> > LIMIT=10
> > a=1
> >
> > while test ${a} -lt ${LIMIT}
> > do
> >   go=`expr ${a} % 2`
> >   if test ${go} -ne 0
> >       then
> >       echo "Odd number ${a}"
> >   fi
> >
> >   a=`expr ${a} + 1`
> >
> > done
> >
> >
> > exit 0
> >
> >
> > In this example, if you change the LIMIT value to 100, the script will print
> > you all odds numbers, while in your example you have to put numbers by your
> > own. In perl it can result as:
> >
> > #!/usr/bin/perl
> >
> > $LIMIT=10;
> > $a=1;
> >
> >     while( $a < $LIMIT ){
> >         if( ($a % 2) !=0 ){
> >             print "Odd number $a\n";
> >         }
> >         $a++;
> >     }
> >
> > exit;
> >
> >
> > Luca
> >
> >
>
>

-- 
Charles D. (Chuck) Harding <charding@llnl.gov>  Voice: 925-423-8879
Senior Computer Associate      ICCD/SDD/ICRMG     Fax: 925-423-8719
Lawrence Livermore National Laboratory      Computation Directorate
Livermore, CA USA  http://www.llnl.gov  GPG Public Key ID: B9EB6601
-- Three out of five people aren't the other two. --

Re: bash question

[Glynn Clements]

Chuck Harding wrote:

> How about
> 
> #!/bin/bash
> for ((i=1;i<11;i+=2))

I haven't heard of this before. It must have been introduced fairly
recently; it isn't supported by bash 2.03 or any 1.x version.

-- 
Glynn Clements <glynn.clements@virgin.net>

Re: bash question

[urgrue]

> I haven't heard of this before. It must have been introduced fairly
> recently; it isn't supported by bash 2.03 or any 1.x version.

it works for me with bash 2.05b

Re: bash question

[Nico Schottelius]

[-- Attachment #1: Type: text/plain, Size: 826 bytes --]

Glynn Clements [Thu, Apr 01, 2004 at 11:53:48PM +0100]:
> Chuck Harding wrote:
> 
> > How about
> > 
> > #!/bin/bash
> > for ((i=1;i<11;i+=2))
> 
> I haven't heard of this before. It must have been introduced fairly
> recently; it isn't supported by bash 2.03 or any 1.x version.

Just to point to another nice shell: zsh4.1.1 does support this
and much more.

I really don't understand why you all bind yourself to bash for scripting!

Bash is slow, big and comfortable. Scripts don't need comfort.

I always use 'ash' (much smaller/faster) for scripts and 'zsh' (much more
nice extensions and still at least as fast as bash) for normal use.

Nico

-- 
Keep it simple & stupid, use what's available.
pgp: 8D0E E27A          | Nico Schottelius
http://nerd-hosting.net | http://linux.schottelius.org

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: bash question

[Joao Victor A. Di Stasi]

/usr/bin/seq 1 2 10
works fine

Scott@Charter wrote:

>I can't get this bash script to work.  It's suppose to print all odd numbers
>from 1 to 10.
>
>#!/usr/bin/bash
>
>LIMIT=10
>a=1
>
>while [ "$a" -le $LIMIT ]
>do
>  if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.
>    then
>      echo -n "$a "
>    fi
>
>echo
>
>let "a+=1"
>done
>echo; echo
>exit 0
>
>
>Can anyone figure out what I am doing wrong?  Can I also see the same thing
>written in Perl?
>
>Thanks for your help.
>
>
>
>Scott D. Smallsreed
>3030 Chipmunk Dr.
>Washoe Valley, NV  89704
>775.849.8411 Hm
>775.849.8412 Fax
>775.722.7773 Cell
>  
>

Re: bash question

[Joao Victor A. Di Stasi]

Ooops!
must be a bash script...
sorry

Joao Victor A. Di Stasi wrote:

> /usr/bin/seq 1 2 10
> works fine
>
> Scott@Charter wrote:
>
>> I can't get this bash script to work.  It's suppose to print all odd 
>> numbers
>> from 1 to 10.
>>
>> #!/usr/bin/bash
>>
>> LIMIT=10
>> a=1
>>
>> while [ "$a" -le $LIMIT ]
>> do
>>  if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.
>>    then
>>      echo -n "$a "
>>    fi
>>
>> echo
>>
>> let "a+=1"
>> done
>> echo; echo
>> exit 0
>>
>>
>> Can anyone figure out what I am doing wrong?  Can I also see the same 
>> thing
>> written in Perl?
>>
>> Thanks for your help.
>>
>>
>>
>> Scott D. Smallsreed
>> 3030 Chipmunk Dr.
>> Washoe Valley, NV  89704
>> 775.849.8411 Hm
>> 775.849.8412 Fax
>> 775.722.7773 Cell
>>  
>>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-admin" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: bash question

[Stephen Samuel]

I'm going to presume that you want to search for a
specific set of numbers, and that the fact that the
fact that they're odd doesn't matter....

In that case, you'd have to use a for loop to seach
thru the list of 'important' values:

for $tval in 1 3 5 7 9; do
	if [ $a -eq $tval ]
	  then
		echo -n "$a "
	fi
done

As far as I know, there's no fast way to search for
one value in a list of candidates.

Scott@Charter wrote:
> I can't get this bash script to work.  It's suppose to print all odd numbers
> from 1 to 10.
> 
> #!/usr/bin/bash
> 
> LIMIT=10
> a=1
> 
> while [ "$a" -le $LIMIT ]
> do
>   if [ "$a" -eq $(1 3 5 7 9) ]     <---------Something not right here.
>     then
>       echo -n "$a "
>     fi
> 
> echo
> 
> let "a+=1"
> done
> echo; echo
> exit 0
> 
> 
> Can anyone figure out what I am doing wrong?  Can I also see the same thing
> written in Perl?


-- 
Stephen Samuel +1(604)876-0426                samuel@bcgreen.com
		   http://www.bcgreen.com/~samuel/
    Powerful committed communication. Transformation touching
      the jewel within each person and bringing it to light.