Shell scripts issue

balakrishnay · 11-27-2009, 12:02 AM

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

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).

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

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

to

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

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

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

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

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.

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

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.

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" )

catkin · 11-27-2009, 10:51 PM

Quote:

Originally Posted by balakrishnay

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

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 · 11-29-2009, 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

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