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.
Related
so the file contains data like
# entertainment
youtube.com
twitch.tv
# research
google.com
wikipedia.com
...
and I would like to pass that file as an argument in a script that would open all lines if they doesn't start with an #. Any clues on how to ?
so far what i have:
for Line in $Lines
do
case "# " in $Line start firefox $Line;; esac
done
some code that could be useful (?):
while read line; do chmod 755 "$line"; done < file.txt
grep -e '^[^#]' inputfile.txt | xargs -d '\n' firefox --new-tab
grep -e '^[^#]': Will print all lines that don't start with a sharp (comments)
xargs -d '\n' firefox --new-tab: Will pass each line that is not blank, as argument to Firefox.
Removes both the lines that start with # and empty lines.
#!/bin/bash
#
while read -r line
do
if [[ $(echo "$line" | grep -Ev "^#|^$") ]]
then
firefox --new-tab "$url" &
fi
done <file.txt
Skip the empty lines and the lines that starts with a #
#!/usr/bin/env bash
while IFS= read -r url; do
[[ "$url" == \#* || -z "$url" ]] && continue
firefox --new-tab "$url" &
done < file.txt
awk 'NF && $1!="#"{print "firefox --new-tab", $0, "&"}' file.txt | bash
I have read the config file which has the below variable:
export BASE_DIR="\usr\usr1"
In the same script I read a file line by line and I wanted to substitute the ${BASE_DIR} with \usr\usr1.
In the script:
while read line; do
echo $line
done <file.txt
${BASE_DIR}\path1 should be printed as \usr\usr1\path1
Tried eval echo and $(( )).
Can use sed, This command will search and replace a value. The dollar sign is the separator.
sed -ie 's$\${BASE_DIR}$\\usr\\usr1$1' hello.txt
You need to set the variable when you read the line that contains the assignment. Then you can replace it later.
#!/bin/bash
while read line; do
if [[ $line =~ ^BASE_DIR= ]]
then basedir=${line#BASE_DIR=}
fi
line=${line/'${BASE_DIR}'/$basedir}
printf "%s\n" "$line"
done < file.txt > newfile.txt
I don't understand why this outer loop exits just because the inner loop can finish.
The $1 refers to a file with a lot of pattern/replacement lines. The $2 is a list of words. The problem is that the outer loop exits already after the first pattern/replacement line. I want it to exit after all the lines in $1 are read.
#!/bin/bash
#Receive SED SCRIPT WORDLIST
if [ -f temp.txt ];
then
> temp.txt
else
touch temp.txt
fi
while IFS='' read -r line || [[ -n "$line" ]];
do
echo -e "s/$line/p" >> temp.txt
while IFS='' read -r line || [[ -n "$line" ]];
do
sed -nf temp.txt $2
done
> temp.txt
done < $1
I understand that you want calculate de sed expressions and write it on a file, and then apply this expresions to other file.
This is so much easier than your are doing it.
First of all, you dont need to check if temp.txt already exists. When you redirect the output of a command to a file, if this file do not exist, it will be created. But if you want to reset the file, I recommend you to use truncate command.
In the body of the script, I don't understand why you put a second while loop to read from a file, but you don't put a file to read.
I think that you need is something like this:
truncate -s 0 sed_expressions.txt
while IFS='' read -r line || [[ -n "$line" ]]; do
echo -e "s/$line/p" >> sed_expressions.txt
done < $1
sed -nf sed_expressions.txt $2 > out_file.txt
Try it and tell me if is this that you need.
Bye!
How can I comment out lines where a certain word can be found in a bash script, using piped UNIX commands (no sed/awk) ?
The comment character is # .
Here is how It could start :
cat $file | grep $word | ...
With GNU bash.
#!/bin/bash
keyword="foo"
while IFS= read -r line; do
[[ "$line" =~ $keyword ]] && line="${line#*#}"
printf "%s\n" "$line"
done < /etc/network/interfaces > /tmp/interfaces_modified
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}"