Tech-Recipes - Latest Comments in bash shell script declaring/creating arrays

Re: bash shell script declaring/creating arrays

Bf Hayati — Fri, 01 Jul 2011 13:58:14 -0000

thats great but can any one know how to use array in loop like ,or know how to change number from decimle into binary plzzzzzzzzzzzzz

Re: bash shell script declaring/creating arrays

Matt Duffy — Wed, 22 Sep 2010 03:19:36 -0000

Hi, just found this site and it's been really helpful so far. I have a problem with assigning the output of a find command into an array. The find command works fine on it's own:

find "$path" $ -type d -o -type f $ -name '[.]*' -print0

where $path is a string with a file system path. This finds all files or directories in a subtree with names that begin with a dot (.svn, .DS_Store, etc). Currently, the output is piped to xargs to delete the files it finds. It uses the -print0 to account for space characters in $path.

What I would like to do is have the output redirected into an array where each array element is a string path value for a file/directory with a dot name. The problem I am having is that there are many files the subtree that have spaces in their name and when the find command output is redirected to the array the space characters in the string cause it to be split into more than one array element.

For example, a string like:
web/Cappuccino/iTunes Layout/Frameworks/AppKit/Resources/.DS_Store

will be split at iTunes<space>Layout to create array elements

array[n] = web/Cappuccino/iTunes
array[n+1] = Layout/Frameworks/AppKit/Resources/.DS_Store

I have tried a number of different syntaxes all with the same result. I feel like it's just a simple error in my variable quoting or something, but I am stuck. I think it should look something like this (but this is wrong):

array=( `find "$path" $ -type f -or -type d $ -name '[.]*' -print0 | xargs -0 -n 1` )

Any suggestions? I am really stuck on this.

Cheers

Re: bash shell script declaring/creating arrays

Varun Avashia — Tue, 14 Sep 2010 04:18:15 -0000

#Initialize commands
init command

echo "Total packages found: " $(rpm -qa | grep -c "some string")

#Search for packages and remove them one by one
for package in $(rpm -qa | grep "some string");
do
echo "Removing " $package
rpm -fe $package
done

#Cleanup
Clean up commands

echo "Remaining packages: " $(rpm -qa | grep -c "some string")

Re: bash shell script declaring/creating arrays

Bill Hernandez — Wed, 18 Aug 2010 10:46:31 -0000

As I was digging through my notes I found this...

------------------------------------------------------
NOTES : Sample code for [ jot ] command...
------------------------------------------------------

# +---------+---------+---------+---------+---------+---------+---------+---------+---------+
RANDOM NUMBERS - print three random numbers between [1 - 500]
[2007.06.08](06:26AM) -> [bhernandez] ~
$ operation=-r ; reps=3 ; begin=1 ; end=500 ; jot $operation $reps $begin $end

15
438
164
# +---------+---------+---------+---------+---------+---------+---------+---------+---------+

SEQUENCE OF NUMBERS

jot 21 -1 1.00 # prints 21 evenly spaced numbers increasing from -1 to 1.

jot 20 5 # prints 20 evenly spaced numbers starting at 5

my_seq=`jot 20 1` # prints 20 evenly spaced numbers starting at 1
echo ${my_seq}

# +---------+---------+---------+---------+---------+---------+---------+---------+---------+
# ROUTINE FROM bh_dir_samples - Example using {sed, wc, jot, and a for loop}
# FOR MORE EXAMPLES SEE --> bh_dir_samples
# +---------+---------+---------+---------+---------+---------+---------+---------+---------+
echo
echo "( 19 ) BASH - Example using {sed, wc, jot, and a for loop}"
my_path="/tmp/state/city/farm/barn/tractor/keys/red/small"
my_str=`echo "$my_path" | sed 's/\// /g'`
my_word_count=`echo $my_str | wc -w` ;
how_many_levels_back=2
max_count=`expr $my_word_count - $how_many_levels_back`
my_seq=`jot $max_count 1` # prints 20 evenly spaced numbers starting at 1

n=1
for arg in $my_str ;
do
if [ $n -gt 0 ]
then
if [ $n -le $max_count ]
then
# echo -n "$n/$arg"
# echo -n "/$arg"
my_result="${my_result}/${arg}"
fi
fi
let "n++"
done

echo "( a ) --> \$my_path = $my_path"
echo "( b ) --> \$how_many_levels_back = $how_many_levels_back"
echo "( c ) --> \$max_count = $max_count"
echo "( d ) --> \$my_seq = `echo $my_seq`" # ( d ) This one shows up on one line
echo "( e ) --> \$my_seq = ${my_seq}" # ( e ) This shows up on separate lines
echo "( f ) --> \$my_seq = `echo $my_seq | sed 's/\n/ /g'`" # ( f ) This one shows up on one line
echo "( g ) --> \$my_result = $my_result"

exit
# +---------+---------+---------+---------+---------+---------+---------+---------+---------+
# RESULTS
# +---------+---------+---------+---------+---------+---------+---------+---------+---------+
( 19 ) BASH - Example using {sed, wc, jot, and a for loop}
( a ) --> $my_path = /tmp/state/city/farm/barn/tractor/keys/red/small
( b ) --> $how_many_levels_back = 2
( c ) --> $max_count = 7
( d ) --> $my_seq = 1 2 3 4 5 6 7
( e ) --> $my_seq = 1
2
3
4
5
6
7
( f ) --> $my_seq = 1 2 3 4 5 6 7
( g ) --> $my_result = /tmp/state/city/farm/barn/tractor/keys

# +---------+---------+---------+---------+---------+---------+---------+---------+---------+
[2007.05.08](04:40PM) -> [bhernandez] ~
$
# +---------+---------+---------+---------+---------+---------+---------+---------+---------+

Re: bash shell script declaring/creating arrays

Ayesha — Tue, 03 Aug 2010 15:13:46 -0000

How can I insert elements in an array from another text file?? I want to read numbers from another text file and insert them in an array??

Re: bash shell script declaring/creating arrays

Ll — Wed, 28 Jul 2010 00:30:08 -0000

did u create it.. wow....

Re: bash shell script declaring/creating arrays

Aparnacomp — Mon, 12 Jul 2010 03:11:30 -0000

to convert a decimal number into its equivalent binary number.....using shell script:

created by APARNA..........

program

echo " program to convert a decimal number into its equivalent binary number......."
echo -e "enter a decimal number...."
read no
d=$no
echo "____________________________________________________________"
r=0
b=0
if test $d -eq 0
then
echo "Binary of 0 is 0..."
else
if test $d -eq 1
then
echo "Binary of 1 is 1..."
else
i=0
echo "d=$d"
while [ $d -ne 1 ]
do
r=`expr $d % 2`
d=`expr $d / 2`
echo " r=$r"
echo "d=$d"
#add one by one element in an array.........
a=( "${a[@]}" "$r" )
i=$i+1
done
a=( "${a[@]}" "$d" )
fi
fi
echo "___________________________________________________________"
len=${#a[*]}
echo "equivalent binary number of $no is....."
j=-1
l=`expr $len - 1`
while [ $l -gt $j ]; do
printf "%2d" ${a[$l]}
let l--
done
printf "\n"
echo " GOOD BYE.........."

Re: bash shell script declaring/creating arrays

asd — Wed, 11 Nov 2009 18:21:22 -0000

asdasdasd

Re: bash shell script declaring/creating arrays

bob.experience — Tue, 28 Apr 2009 07:35:28 -0000

Well done man! Thanks for the tip!

Re: bash shell script declaring/creating arrays

Manav — Mon, 13 Apr 2009 05:49:19 -0000

Good one

Re: bash shell script declaring/creating arrays

Erik J — Thu, 29 Jan 2009 09:00:11 -0000

Reading a line, while preseriving whitespaces seems har dto do from a file

You can do it this way:

cat $file | while read line; do
		echo "$line";
done

Re: bash shell script declaring/creating arrays

secoif — Thu, 22 Jan 2009 07:19:51 -0000

One way to merge two arrays:

#existing array
existing=(item1, item2, item3);

#items to merge (including an item requiring correct quoting)
merge=(item4 item5 "${item6}*");

count=${#existing[@]};
num_new_items=${#merge[@]};
# this loop appends items to the end of the array
for (( i=0;i<$num_new_items;i++)); do
echo ${i};
existing[$count]=${merge[${i}]};
let count+=1;
done

count=${#existing[@]}
for (( i=0;i<$count;i++)); do
echo ${existing[${i}]};
done

Re: bash shell script declaring/creating arrays

Punit — Tue, 16 Dec 2008 08:01:50 -0000

Here is another method of adding elements in the array.. It works best with korn shell

set -A array_example 1 2 3 4 5
i=0
echo ${array_example[$i]}

Re: bash shell script declaring/creating arrays

Barun — Mon, 08 Dec 2008 05:09:04 -0000

Wow!!! The trick for initializing an array from a file is superb!

Re: bash shell script declaring/creating arrays

move all array — Mon, 13 Jun 2005 11:05:13 -0000

here is another method to add elements to an array

for foo in $(find -type f -iname "*.png" -printf "%fn"); do file[${#file[*]}]=$foo done

will create an array of all png files