Shell Scripting - Using Bourne shell : if you enter A B C D E F G.......................n after the command,how will y

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Using Bourne shell : if you enter A B C D E F G.......................n after the command,
how will you write a programme to reverse these positional parameters?

Total Answers and Comments: 4

Last Update: November 07, 2008 Asked by: Nehashri

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Best Rated Answer

—

Submitted by: UncaAlby

str="alpha beta gamma"
echo $str | awk '{
for (i=NF; i>0; i--) printf ("%s ",$i);
printf("n");
}'

Results:

gamma beta alpha

If you're talking about parameters passed into a Shell script, that can be modified to the following:

echo $* | awk '{
for (i=NF; i>0; i--) printf ("%s ",$i);
printf("n");
}'

The previous answer using "awk" reversed all the characters, resulting in:

ammag ateb ahpla

Which I don't think is what was meant in the phrase, positional parameters.

Although, if reversing all the characters is what you wanted, then that's one good way to do it.

Above answer was rated as good by the following members:
jrgalaura

February 09, 2007 03:45:38

Jitu

RE: Using Bourne shell : if you enter A B C D E F G......

Hi All,

You can use this command:-

$ echo "$@" | rev

Please make me clear if i am wrong.

Thanks,

Jitu

Is this answer useful? Yes | No

0 1

Overall Rating: -1

August 12, 2007 03:28:35

Amit

Possible Another Solution

i=$#
while(($i>=0))
do
echo $i
((i=$i-1))
done

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0 1

Overall Rating: -1

May 27, 2008 03:19:40

kamalakar Navana

Member Since: May 2008 Contribution: 1

RE: Using Bourne shell : if you enter A B C D E F G.......................n after the command,how will you write a programme to reverse these positional parameters?

str="A B C D E F G"
echo $str | awk '{
for(i=length($0);i>=1;i--)
printf("%s",substr($0,i,1));
}'

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0 1

Overall Rating: -1

November 07, 2008 04:40:26

UncaAlby

Member Since: October 2008 Contribution: 13

RE: Using Bourne shell : if you enter A B C D E F G.......................n after the command,how will you write a programme to reverse these positional parameters?

str="alpha beta gamma"
echo $str | awk '{
for (i=NF; i>0; i--) printf ("%s ",$i);
printf("n");
}'

Results:

gamma beta alpha

If you're talking about parameters passed into a Shell script, that can be modified to the following:

echo $* | awk '{
for (i=NF; i>0; i--) printf ("%s ",$i);
printf("n");
}'

The previous answer using "awk" reversed all the characters, resulting in:

ammag ateb ahpla

Which I don't think is what was meant in the phrase, positional parameters.

Although, if reversing all the characters is what you wanted, then that's one good way to do it.

Is this answer useful? Yes | No

1 0

Overall Rating: +1

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