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HELP! Who can solve this bash script?

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HELP! Who can solve this bash script?

Jun 1st, 2007

Thank you very much for who can solve this bash script:
"Create a bash procedure createdata that creates collections (directories) that that will have to contain a random number, comprised between 300 and 600, of binary files of dimension comprised between 10 Kbytes and 30 kbytes.
Also the names of the files are random and are composed from 20 chars plus the jpg extension."

Working sample:

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Shell Scripting Syntax (Toggle Plain Text)

createdata /data 20
 
result:
 
/data
      tlc01
             collection001
                             ttretdgdfgasjojgvao.jpg
                             grtghgfhysystudbbnh.jpg
                             ...
             ...
             collection019
                             ...

it must create therefore beyond to the directory given (data) the subdirectory tlc01, then the 20 collections (subdirectories of tlc01)

Sorry for my english, hope you understand..
Thanks indeed for who can help me :-)

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Re: HELP! Who can solve this bash script?

Jun 1st, 2007

Have you tried to do it on your own? Or did you just run here hoping that someone would do your homework for you?

I'm here to prove you wrong.

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Re: HELP! Who can solve this bash script?

Jun 1st, 2007

yes I tried this:

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 Shell Scripting Syntax (Toggle Plain Text) 
#!/bin/sh
mkdir $1
number=$2
while $number > 0; do
    mkdir collectionnumber$number
    numbermaxfile4folder=here I have to assign a RANDOM BETWEEN 300 AND 600 (how ???)
    firstpartoffile=$(date) 
    chars=$RANDOM
    echo chars > $firstpartoffile000000.jpg (to fill up a file of an amount of bytes..it should be between 10 and 30..)
done
number=$number-1
cp -r collection$number /data
#!/bin/sh
mkdir $1
number=$2
while $number > 0; do
    mkdir collectionnumber$number
    numbermaxfile4folder=here I have to assign a RANDOM BETWEEN 300 AND 600 (how ???)
    firstpartoffile=$(date) 
    chars=$RANDOM
    echo chars > $firstpartoffile000000.jpg (to fill up a file of an amount of bytes..it should be between 10 and 30..)
done
number=$number-1
cp -r collection$number /data

can anyone help me to solve the full version? This is incomplete and I think also wrong..
Please help I'm totally newbie

((

Last edited by alexxxprog; Jun 1st, 2007 at 5:32 pm.

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Re: HELP! Who can solve this bash script?

Jun 1st, 2007

•

Originally Posted by alexxxprog

...
numbermaxfile4folder=here I have to assign a RANDOM BETWEEN 300 AND 600 (how ???)
...

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
# start=300
# end=600
# echo $(($RANDOM % ( $end - $start + 1 ) + $start))
401
# start=300
# end=600
# echo $(($RANDOM % ( $end - $start + 1 ) + $start))
401

•

(to fill up a file of an amount of bytes..it should be between 10 and 30..)

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
chars=(
    a b c d e f g h i j k l m n o p q r s t u v w x y z \
    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \
    1 2 3 4 5 6 7 8 9 0
)
 
function random_string {
    length=${1:-10}
    for ((i = 0; i < length; i++)); do
        echo -n ${chars[ (( ${RANDOM} % ${#chars[@]} )) ]}
    done
    echo
}
 
random_string 20
chars=(
    a b c d e f g h i j k l m n o p q r s t u v w x y z \
    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \
    1 2 3 4 5 6 7 8 9 0
)

function random_string {
    length=${1:-10}
    for ((i = 0; i < length; i++)); do
        echo -n ${chars[ (( ${RANDOM} % ${#chars[@]} )) ]}
    done
    echo
}

random_string 20

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Re: HELP! Who can solve this bash script?

Jun 2nd, 2007

thank you very much ghostdog74!

My code then is this:

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 Shell Scripting Syntax (Toggle Plain Text) 
#!/bin/sh
mkdir data
cd $data
number=$2
while $number > 0; do
    mkdir collection$number
    cd $collection$number
    numberoffilemax=$(($RANDOM % ( $600 - $300 + 1 ) + $300))
    while $numberoffilemax > 0; do
        firstpartoffile=$(date) 
        chars=random_string()
        echo chars > $firstpartoffile000000.jpg
        numberoffilemax=$numerofilemax-1
    done
    cd .. 
    number=$number-1
done
 
chars=(
    a b c d e f g h i j k l m n o p q r s t u v w x y z \
    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \
    1 2 3 4 5 6 7 8 9 0
)
 
function random_string {
    length=${1:-10}
    for ((i = 0; i < length; i++)); do
        echo -n ${chars[ (( ${RANDOM} % ${#chars[@]} )) ]}
    done
    echo
}
#!/bin/sh
mkdir data
cd $data
number=$2
while $number > 0; do
    mkdir collection$number
    cd $collection$number
    numberoffilemax=$(($RANDOM % ( $600 - $300 + 1 ) + $300))
    while $numberoffilemax > 0; do
        firstpartoffile=$(date) 
        chars=random_string()
        echo chars > $firstpartoffile000000.jpg
        numberoffilemax=$numerofilemax-1
    done
    cd .. 
    number=$number-1
done

chars=(
    a b c d e f g h i j k l m n o p q r s t u v w x y z \
    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \
    1 2 3 4 5 6 7 8 9 0
)

function random_string {
    length=${1:-10}
    for ((i = 0; i < length; i++)); do
        echo -n ${chars[ (( ${RANDOM} % ${#chars[@]} )) ]}
    done
    echo
}

Thank you again!

Last edited by alexxxprog; Jun 2nd, 2007 at 6:42 am.

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Re: HELP! Who can solve this bash script?

Jun 4th, 2007

•

Originally Posted by ghostdog74

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Shell Scripting Syntax (Toggle Plain Text)
# start=300
# end=600
# echo $(($RANDOM % ( $end - $start + 1 ) + $start))
401
# start=300 # end=600 # echo $(($RANDOM % ( $end - $start + 1 ) + $start)) 401

tryrandom.bash:

#!/bin/bash
start=300
end=600
echo $(($RANDOM % ( $end - $start + 1 ) + $start))

tryrandom.bash: line 2: 19345 % -1 + : syntax error: operand expected (error token is " ")

why?

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Re: HELP! Who can solve this bash script?

Jun 4th, 2007

•

Originally Posted by ghostdog74

[code]
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Shell Scripting Syntax (Toggle Plain Text)
chars=(
    a b c d e f g h i j k l m n o p q r s t u v w x y z \
    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \
    1 2 3 4 5 6 7 8 9 0
)
 
function random_string {
    length=${1:-10}
    for ((i = 0; i < length; i++)); do
        echo -n ${chars[ (( ${RANDOM} % ${#chars[@]} )) ]}
    done
    echo
}
 
random_string 20
chars=( a b c d e f g h i j k l m n o p q r s t u v w x y z \ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z \ 1 2 3 4 5 6 7 8 9 0 ) function random_string { length=${1:-10} for ((i = 0; i < length; i++)); do echo -n ${chars[ (( ${RANDOM} % ${#chars[@]} )) ]} done echo } random_string 20

how to assign the value of the function in a shell script?

thanks!

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Re: HELP! Who can solve this bash script?

Jun 4th, 2007

•

Originally Posted by alexxxprog

tryrandom.bash:

#!/bin/bash
start=300
end=600
echo $(($RANDOM % ( $end - $start + 1 ) + $start))

tryrandom.bash: line 2: 19345 % -1 + : syntax error: operand expected (error token is " ")

why?

try typing the commands on the shell prompt and see.

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Re: HELP! Who can solve this bash script?

Jun 4th, 2007

•

Originally Posted by alexxxprog

how to assign the value of the function in a shell script?

thanks!

put a return statement in the functoin. then call it and use $? to catch the value

 Help with Code Tags 
 Shell Scripting Syntax (Toggle Plain Text) 
 
# function test() { return 1; }
# var=$(test)
# echo $?
1
# function test() { return 1; }
# var=$(test)
# echo $?
1