getting the error when using sed in a loop- sed:no input files

Question

I am using sed within a while loop to remove the trailing blank spaces from a file containing a list of files. The blank spaces are being removed. But I'm getting the message sed:no input files.

Following is the while loop I am using:

while IFS= read -r line; 
        do
            echo "tester: $line"
            sed -i 's/\s*$//' $line ;
        done < file_list.txt

Yes. the piece of code is working. But I am getting messages of 'sed:no input files' — Raghunath Choudhary, Nov 28 '17 at 11:25
No, what do you see if you do tail -1 file_list.txt? If you don't see anything except an empty line then you need to delete that empty line. — B Layer, Nov 28 '17 at 12:00
Let me explain deeper. I have a file file_list.txt which contains a list of filenames to be processed. And for all the files present in the file_list.txt I have to remove the trailing blank spaces and extra newline characters. I am using while loop to read the file names and process using sed command. — Raghunath Choudhary, Nov 28 '17 at 12:43
When $line is empty, your sed command becomes sed -i 's/\s*$//' ; -- with no file. You must quote the variable: sed -i 's/\s*$//' "$line" — glenn jackman, Nov 28 '17 at 13:45
When I quote the variable , the error says 'no such file or directory' — Raghunath Choudhary, Nov 28 '17 at 14:05

Jeff Schaller · Accepted Answer · 2017-11-28T23:01:15.610

As Ipor and glenn have both said, based on your report from B Layer's comment regarding tail -1 file_list.txt, since there is a blank line at the end of that file, when the while loop reads that blank line, the $line variable gets assigned an empty value, leaving no filename for sed to process.

$ cat i
file1
file2

$ while IFS= read -r line; do printf -- "-->%s<--\n" "$line"; done < i
-->file1<--
-->file2<--
--><--

The fix here is to delete that trailing blank line from file_list.txt, or wrap a test around your actual processing to test for the existence of the file:

# do ...
if [ -f "$line" ]
then
  # process file
fi
# done ...

and always quote your variables!

score 0 · Answer 2 · answered Jun 26 '19 at 10:13

0

Had same issue, for me it was because I did not pass the input file to sed CMD

Example:

boy=$1
boy2=$2
boy3=$3
while IFS="," read -r col1 col2
do
 if [ "$col1" == "oke" ]; then

    sed -i "s/$col2/$boy/g" test.txt
  fi
done < test.txt

answered Jun 26 '19 at 10:13

innocent.anigbo

1

getting the error when using sed in a loop- sed:no input files

2 Answers2