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- - Shell scripts issue (https://www.linuxquestions.org/questions/linux-general-1/shell-scripts-issue-771836/)

balakrishnay

11-27-2009 12:02 AM

Shell scripts issue

Hi all,

My scripts looks like this .. when i execute this script its says file does not exist even though file is present physically and if the file does not present in the file system then the output is null.

I am wrong somewhere .. ??

echo " enter file "
read name
for i in `find /apps12i -type f -name $name -printf %f `
do
if [ -e $i ]
then
echo "file exists"
else
echo "not exists "
fi
done

2. I want to send multiple attachments using mutt is possible ?

3. I want to change from mail address when i am sending mails through mutt.

Regards

ghostdog74

11-27-2009 12:05 AM

use a while read loop instead

Code:

find ... | while read file

do

  echo $file

done

catkin

11-27-2009 12:29 AM

You will get a better response to questions 2 and 3 if you put them in separate threads with relevant titles.

Regards the existing file(s) that is/are reported as not existing you can see which files are being tested by changing the code to

Code:

echo " enter file "

read name

for i in `find /apps12i -type f -name $name -printf %f `

do

    echo "DEBUG: file name is '$i'"

    if [ -e $i ]

    then

        echo "file exists"

    else

        echo "not exists "

    fi

done

File names including whitespace characters such as space will not be handled correctly by the script.

Regards null output for non-existing files, that is expected. The find command will not produce any output so the loop code will not be executed.

BTW:

the most robust form of looping with the loop variable set to successive file pathnames is

Code:

find /apps12i -type f -print0 | while IFS= read -r -d '' i do <loop command(s)> done
the preferred form of testing is [[ <test expression> ]] rather than [ <test expression> ]
the preferred form of command substitution is $( <command(s)> ) rather than `<command(s)>`.
It's easier to read if you put it in code tags (that's a link to instructions or you may prefer to use "Advanced Edit" mode which has a # button for code tags).

balakrishnay

11-27-2009 12:52 AM

Thanks for your reply .. but i am not able to understand proplery

I have rewritten like this .. but still the same problem exists . can you please correct me.

I request you to please elaborate this while IFS= read -r -d '' this stmt.

echo " enter file "
read name
i=`find /apps12i -type f -name $name -print0` | while IFS= read -r -d '' $i
do
echo $i
done

Quote:

Originally Posted by catkin (Post 3771029)

Code:

echo " enter file "

read name

for i in `find /apps12i -type f -name $name -printf %f `

do

    echo "DEBUG: file name is '$i'"

    if [ -e $i ]

    then

        echo "file exists"

    else

        echo "not exists "

    fi

done

the most robust form of looping with the loop variable set to successive file pathnames is

Code:

find /apps12i -type f -print0 | while IFS= read -r -d '' i do <loop command(s)> done
the preferred form of testing is [[ <test expression> ]] rather than [ <test expression> ]
the preferred form of command substitution is $( <command(s)> ) rather than `<command(s)>`.
It's easier to read if you put it in code tags (that's a link to instructions or you may prefer to use "Advanced Edit" mode which has a # button for code tags).

ghostdog74

11-27-2009 01:08 AM

Code:

echo " enter file "

read name

find /apps12i -type f -name "$name"  | while read -r FILE

do

    echo $FILE

done

balakrishnay

11-27-2009 02:03 AM

Thanks for your reply ..... what if file does not exist .. my requirement is , if the file does not exist it should give me files does not exist message.

Regards

Quote:

Originally Posted by ghostdog74 (Post 3771047)

Code:

echo " enter file "

read name

find /apps12i -type f -name "$name"  | while read -r FILE

do

    echo $FILE

done

catkin

11-27-2009 02:14 AM

You changed

Code:

find /apps12i -type f -print0 | while IFS= read -r -d '' i

Code:

i=`find /apps12i -type f -name $name -print0` | while IFS= read -r -d '' $i

The change will prevent it working.

while IFS= read -r -d '' means "set IFS to the empty string and with that setting in use for this command only, run the "read" shell built-in command not treating any \ characters specially and only accepting the newline character as end-of-line indicator. The shell uses the characters in IFS as word-separators when parsing input into "words". The net effect of all this gobbledygook is to transfer exactly the file names that "find" prints, regardless of any weird characters in file names.

It is very defensive and robust. Most of the time ghostdog74's suggestion works perfectly well -- and is a lot simpler! :)

catkin

11-27-2009 02:18 AM

Quote:

Originally Posted by balakrishnay (Post 3771080)

Thanks for your reply ..... what if file does not exist .. my requirement is , if the file does not exist it should give me files does not exist message.

Regards

Code:

echo " enter file "

read name

found='NO'

find /apps12i -type f -name "$name"  | while read -r FILE

do

    echo $FILE

    found='YES'

done



[[ "$found" == 'NO' ]] && echo "File '$name' not found"

balakrishnay

11-27-2009 02:33 AM

i have executed this but .. the output is wrong ..

even though file exists .. its giving me file not found. i am really sorry please bare with me ..

testinst1.koel.co.in/apps12i]./check.sh
enter file
bala.txt
File 'bala.txt' not found
testinst1.koel.co.in/apps12i]./check.sh
enter file
APXVDRAL.rdf
/apps12i/oracle/KIRAN/apps/apps_st/appl/ap/12.0.0/reports/US/APXVDRAL.rdf
File 'APXVDRAL.rdf' not found

Regards

Quote:

Originally Posted by catkin (Post 3771087)

Code:

echo " enter file "

read name

found='NO'

find /apps12i -type f -name "$name"  | while read -r FILE

do

    echo $FILE

    found='YES'

done



[[ "$found" == 'NO' ]] && echo "File '$name' not found"

catkin

11-27-2009 06:52 AM

Quote:

Originally Posted by balakrishnay (Post 3771099)

Better we "bear" with you -- "bare" is something different! :)

Sorry my stupid mistake -- the "while" loop is run in a subshell so any variables set in it are lost when it exits. :redface:

This one is tested

Code:

echo " enter file "

read name

while read FILE

do

    if [[ "$FILE" == '' ]]; then

        echo "$name not found"

    else

        echo "$FILE found"

    fi

done <<< $( find . -type f -name "$name" )

balakrishnay

11-27-2009 10:00 PM

Thank you !! very much. Finally it worked.

But i didn't understand the logic behind this .. can you please explain this.

echo " enter file "
read name
while read FILE
do
if [[ "$FILE" == '' ]]; then
echo "$name not found"
else
echo "$FILE found"
fi
done <<< $( find . -type f -name "$name" )

Regards

Quote:

Originally Posted by catkin (Post 3771310)

Code:

echo " enter file "

read name

while read FILE

do

    if [[ "$FILE" == '' ]]; then

        echo "$name not found"

    else

        echo "$FILE found"

    fi

done <<< $( find . -type f -name "$name" )

catkin

11-27-2009 10:51 PM

Quote:

Originally Posted by balakrishnay (Post 3771971)

can you please explain this.

The input to the read comes, non-intuitively, at the end of the do-done from a here string (scroll down to section 3.6.7) with the string itself being the output of $( find ...).

If the file does not exist, there is no output from the find command so the string is empty, hence the if [[ "$FILE" == '' ]].

It's easier to read your code if you put it in code tags (that's a link to instructions or you may prefer to use "Advanced Edit" mode which has a # button for code tags).

balakrishnay

11-27-2009 11:12 PM

Thanks .. nice explanation .

Regards

Quote:

Originally Posted by catkin (Post 3771990)

balakrishnay

11-29-2009 10:29 PM

Hi Catkin,

My requirements seems to be changed again . I will explain you what i am trying to achieve.

I want to find multiple files in different directories with one find command and send this files to developers. This is my requirement and changed the code accordingly but it seems to be not working .

Code:

echo " enter how many files "

read no

echo " enter file "

read name

if [ $no = 1 ] ; then

while read FILE

do

    if [[ "$FILE" == '' ]]; then

        echo "$name not found"

    else

        echo "$FILE found"

done <<< $( find . -type f -name "$name" )

else

if [ no -gt 1 ] ; then

for j in {1..$no}

do

echo " enter file names "

read name

fn="-o -name $name"

done

while read FILE

do

    if [[ "$FILE" == '' ]]; then

        echo "$name not found"

    exit 1

    else

        echo "$FILE found"

    fi

done <<< $( find . -type f -name "$name" $fn )

fi

fi

Tried executing this code but it giving me error ..

testinst1.koel.co.in/apps12i]./check.sh
enter how many files
1
enter file
bala.txt
./check.sh: line 12: syntax error near unexpected token `done'
./check.sh: line 12: `done <<< $( find . -type f -name "$name" )'

Regards

Bala

Quote:

Originally Posted by balakrishnay (Post 3772003)

Thanks .. nice explanation .

Regards

chrism01

11-30-2009 12:14 AM

Code:

while

do

.

.

. 

done < file

takes only one '<'
http://tldp.org/LDP/abs/html/redircb.html

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