I am reading a text file with the following code and I want to echo the output on the same line on screen. Preceding to that, I want to do some trimming with sed but at the end I failed to echo the output on the same line.
while read line; do {
var="$(echo $line | sed 's/<[^>]*>//g')";
echo -n "$var"
} done < file.txt
So if I echo -n "$line" it prints the output on the same line but when `sed' comes in it failed to do so. What is it that I am doing wrong ?
Related
I have this input file
gb|KY798440.1|
gb|KY842329.1|
MG082893.1
MG173246.1
and I want to get all the characters that are between the "|" or the full line if there is no "|". That is a desired output that looks like
KY798440.1
KY842329.1
MG082893.1
MG173246.1
I wrote:
while IFS= read -r line; do
if [[ $line == *\|* ]] ; then
sed 's/.*\|\(.*\)\|.*/\1/' <<< $line >> output_file
else echo $line >> output_file
fi
done < input_file
Which gives me
empty line
empty line
MG082893.1
MG173246.1
(note: empty line means an actual empty line - it doesn't actually writes "empty line")
The sed command works on a single example (i.e. sed 's/.*\|\(.*\)\|.*/\1/' <<< "gb|KY842329.1|" outputs KY842329.1) but within the loop it just does a line return. The else echo $line >> output_file seems to work.
Bare sed:
$ sed 's/^[^|]*|\||[^|]*$//g' file
Output:
KY798440.1
KY842329.1
MG082893.1
MG173246.1
You could do
sed '/|/s/[^|]*|\([^|]*\)|.*/\1/' input
or
awk 'NF>1 {print $2} NF < 2 { print $1}' FS=\| input
or
sed -e 's/[^|]*|//' -e 's/|.*//' input
I have a text file foo.txt with the below text as content,
1
2
3
4
5
I have a shell script,
file="foo.txt"
while IFS= read -r line
do
echo "$line"
done < "$file"
But this prints only till 4.
Actual Output:
1
2
3
4
How to get the expected output as below?
Expected Output:
1
2
3
4
5
This is due to missing line break in the last line of your input file.
You can use this loop to read everything:
while IFS= read -r line || [ -n "$line" ]; do
echo "$line"
done < "$file"
For the last line without line break, read doesn't return a success hence [ -n "$line" ] check is done to make sure to print it when $line is not empty.
PS: If you don't mind changing your input file then use printf to append a newline using:
printf '\n' >> "$file"
And then read normally:
while IFS= read -r line; do
echo "$line"
done < "$file"
I need you help on this;
I am currently trying to apply a sed command to lines from a file.
2014-08-05T09:29:13+01:00 (INFO:3824.87075728): [27219] [ <email#domain.com>] A message from <user1#domain.com> source <asdfg> this is a test.
I need to apply this sed cmd to this line but keep this others that does not have 'this is a test'
pattern="this\ is\ a test"
while IFS='' read -r line; do
if [[ $line = *"${pattern}"* ]]; then
sed 's/\[ .*\(source\)/\1/g' ${line}
else
echo "${line}"
fi
done < ${INPUT} > ${OUPUT}
I have set the input and output; however ideally keeping the same file would be ideal.
Thank you for your input.
You don't need a loop for this. Use this sed:
sed -i.bak '/this is a test/s/\[ .*\(source\)/\1/g' "${INPUT}"
I have a read loop that is reading a variable but not behaving the way I expect. I want to read every line of my variable and process each one. Here is my loop:
while read -r line
do
echo $line | sed 's/<\/td>/<\/td>$/g' | cut -d'$' -f2,3,4 >> file.txt
done <<< "$TABLE"
I expect it to process every line of the file but instead it just does the first one. If my the middle is simply echo $line >> file.txt it works as expected. What's going on here? How do I get the behavior I want?
It seems your lines are delimited by \r instead of \n.
Use this while loop to iterate the input with use of read -d $'\r':
while read -rd $'\r' line; do
echo "$line" | sed 's~</td>~</td>$~g' | cut -d'$' -f2,3,4 >> file.txt
done <<< "$TABLE"
If $TABLE contains a multi-line string, I recommend
printf '%s\n' "$TABLE" |
while read -r line; do
echo $line | sed 's/<\/td>/<\/td>$/g' | cut -d'$' -f2,3,4 >> file.txt
done
This is also more portable since the '<<<' operator for here-strings is not POSIX.
I am trying to write a script which reads a text file and saves each line to a string. I would also like the script to skip any lines which start with a hash symbol. Any suggestions?
You should not leave skipping lines to ksh. E.g. do this:
grep -v '^#' INPUTFILE | while IFS="" read line ; do echo $line ; done
And instead of the echo part do whatever you want.
Or if ksh does not support this syntax:
grep -v '^#' INPUTFILE > tmpfile
while IFS="" read line ; do echo $line ; done < tmpfile
rm tmpfile
while read -r line; do
[[ "$line" = *( )#* ]] && continue
# do something with "$line"
done < filename
look for "File Name Patterns" or "File Name Generation" in the ksh man page.