This is my code
title=""
line=""
fname=$1
numoflines=$(wc -l < $fname)
for ((i=2 ; i<=$numoflines ; i++))
do
...
done
In the for loop i want to print the first word of every line into $title
and the rest of the line without the first word into $line
(using bash)
tnx
I am assuming that by print to a variable you mean add the contents of each line to the variable. To do this, you can use the bash built-in function read:
while read -r t l; do title+="$t"; line+="$l"; done < "$fname"
This will add the first word of every line to $title and the rest of the line to $line.
You can do some like this:
echo "$fname"
This is my line.
My cat is green.
title=$(awk '{print $1}' <<< "$fname")
line=$(awk '{$1="";sub(/^ /,"")}1' <<< "$fname")
echo "$title"
This
My
echo "$line"
is my line.
cat is green.
Alternative approach using the cut command:
file="./myfile.txt"
title=$(cut -f1 -d ' ' "$file")
line=$(cut -f2- -d ' ' "$file")
#check print
pr -tm <(echo -e "TITLES\n$title") <(echo -e "LINES\n$line")
for the next myfile.txt
My cat is green.
Green cats are strange.
prints
TITLES LINES
My cat is green.
Green cats are strange.
do
Tempo="$( sed -n "${i} {s/^[[:blank:]]*\([^[:blank:]]*\)[[:blank:]]*\(.*\)/title='\1';line='\2'/p;q;}" ${fname} )"
eval "${Tempo}"
done
# or
do
sed -n "${i} {p;q;}" | read Line Title
# but this does not keep content available on each OS/shell
done
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", $0, "&"}' file.txt | bash
The examplary code below writes hi in a new line at every iteration. Is there a way to prevent this?
#!/bin/bash
while read line; do
var=$(echo $line | cut -d \, -f 2)
echo -n " $var"
done < file.csv > output.txt
Desired output is a concatenation of '$var's at each iteration. The code is run in OS X.
[Resolved]
In most cases of similar problems, klashww's answer would be what you want to try so that I would accept it as the answer. Yet, in my case, such options all failed in fixing the bug. The behavior was due to non-displayed character '^M' at the end of each line, since the file was coming from windows. I relearned that we should make sure to get rid of '^M' before processing it in bash via the line below. After that, the original code works fine.
tr -d '\015' < file > newfile
You might like to try using pure bash:
while IFS=',' read nu1 var nu2; do
echo -n " $var"
done < file.csv > output.txt
nu: "not used"
Use echo "hi\c" instead of echo -n "hi" or printf if avaliable , example printf "hi".
In your example, this should work:
while read line; do
var=$(echo $line | cut -d \, -f 2)
printf " $var"
done < file.csv > output.txt
Or you can use a better tool:
awk -F\, '{printf " "$2}' file.csv > output.txt
If everything fails tr brute force:
echo " $var"| tr -d '\n'
For every line in my file, I want to print everything on that line before the 4th dash.
Input:
TCGA-HC-8216-10A-11D-A323-01
TCGA-J4-8200-10A-11D-A323-01
TCGA-EJ-A65E-10A-11D-A323-01
and I want to split each line on the fourth dash "-"
Output:
TCGA-HC-8216-10A
TCGA-J4-8200-10A
TCGA-EJ-A65E-10A
I know I can split on every dash like this:
#!/usr/bin/env bash
IN="TCGA-HC-8216-01A-11D-A323-01
TCGA-J4-8200-10A-11D-A323-01
TCGA-EJ-A65E-10A-11D-A323-01"
arr=$(echo $IN | tr "-" "\n")
for x in $arr
do
echo "> [$x]"
done
but this splits and prints each part of the string between every dash.
Use cut
cut -d- -f1-4 <<'EOF'
TCGA-HC-8216-01A-11D-A323-01
TCGA-J4-8200-10A-11D-A323-01
TCGA-EJ-A65E-10A-11D-A323-01
EOF
You are cutting your input on -d (delimiter) of - and returning -f (fields) 1-4, one through four.
#!/bin/bash
IN="TCGA-HC-8216-01A-11D-A323-01
TCGA-J4-8200-10A-11D-A323-01
TCGA-EJ-A65E-10A-11D-A323-01"
arr=$(echo "$IN" | cut -d '-' -f1-4)
echo "$arr"
Prints:
TCGA-HC-8216-01A
TCGA-J4-8200-10A
TCGA-EJ-A65E-10A
Using pure bash and pattern matching:
#!/bin/bash
IN="TCGA-HC-8216-01A-11D-A323-01
TCGA-J4-8200-10A-11D-A323-01
TCGA-EJ-A65E-10A-11D-A323-01"
re='([^-]+-){3}[^-]+'
for line in $IN
do
if [[ $line =~ $re ]]; then
trunc=${BASH_REMATCH[0]}
fi
echo "$trunc"
done
Output:
TCGA-HC-8216-01A
TCGA-J4-8200-10A
TCGA-EJ-A65E-10A
Using grep with ERE:
arr=$(echo "$IN" | grep -oE "^([^-]*-){3}[^-]*")
With BRE:
arr=$(echo "$IN" | grep -o "^\([^-]*-\)\{3\}[^-]*")
Example:
#!/bin/bash
IN="TCGA-HC-8216-01A-11D-A323-01
TCGA-J4-8200-10A-11D-A323-01
TCGA-EJ-A65E-10A-11D-A323-01"
arr=$(echo "$IN" | grep -oE "^([^-]*-){3}[^-]*")
for x in $arr
do
echo "> [$x]"
done
Output:
> [TCGA-HC-8216-01A]
> [TCGA-J4-8200-10A]
> [TCGA-EJ-A65E-10A]
I have a file which contains one line of text with tabs
echo -e "foo\tbar\tfoo2\nx\ty\tz" > file.txt
I'd like to get the first column with cut. It works if I do
$ cut -f 1 file.txt
foo
x
But if I read it in a bash script
while read line
do
new_name=`echo -e $line | cut -f 1`
echo -e "$new_name"
done < file.txt
Then I get instead
foo bar foo2
x y z
What am I doing wrong?
/edit: My script looks like that right now
while IFS=$'\t' read word definition
do
clean_word=`echo -e $word | external-command'`
echo -e "$clean_word\t<b>$word</b><br>$definition" >> $2
done < $1
External command removes diacritics from a Greek word. Can the script be optimized any further without changing external-command?
What is happening is that you did not quote $line when reading the file. Then, the original tab-delimited format was lost and instead of tabs, spaces show in between words. And since cut's default delimiter is a TAB, it does not find any and it prints the whole line.
So quoting works:
while read line
do
new_name=`echo -e "$line" | cut -f 1`
#----------------^^^^^^^
echo -e "$new_name"
done < file.txt
Note, however, that you could have used IFS to set the tab as field separator and read more than one parameter at a time:
while IFS=$'\t' read name rest;
do
echo "$name"
done < file.txt
returning:
foo
x
And, again, note that awk is even faster for this purpose:
$ awk -F"\t" '{print $1}' file.txt
foo
x
So, unless you want to call some external command while looping the file, awk (or sed) is better.
I have this block of code:
while IFS=$'\n' read -r line || [[ -n "$line" ]]; do
if [ "$line" != "" ]; then
echo -e "$lanIP\t$line" >> /tmp/ipList;
fi
done < "/tmp/includeList"
I know this must be really simple. But I have another list (/tmp/excludeList). I only want to echo the line within my while loop if the line ins't found in my excludeList. How do I do that. Is there some awk statement or something?
You can do this with grep alone:
$ cat file
blue
green
red
yellow
pink
$ cat exclude
green
pink
$ grep -vx -f exclude file
blue
red
yellow
The -v flag tells grep to only output the lines in file that are not found in exclude and the -x flags forces whole line matching.
use grep
while IFS=$'\n' read -r line || [[ -n "$line" ]]; do
if [[ -n ${line} ]] \
&& ! grep -xF "$line" excludefile &>/dev/null; then
echo -e "$lanIP\t$line" >> /tmp/ipList;
fi
done < "/tmp/includeList"
the -n $line means if $line is not empty
the grep returns true if $line is found in exclude file which is inverted by the ! so returns true if the line is not found.
-x means line matched so nothing else can appear on the line
-F means fixed string so if any metacharacters end up in $line they'll be matched literally.
Hope this helps
With awk:
awk -v ip=$lanIP -v OFS="\t" '
NR==FNR {exclude[$0]=1; next}
/[^[:space:]]/ && !($0 in exclude) {print ip, $0}
' /tmp/excludeList /tmp/includeList > /tmpipList
This reads the exclude list info an array (as the array keys) -- the NR==FNR condition is true while awk is reading the first file from the arguments. Then, while reading the include file, if the current line contains a non-space character and it does not exist in the exclude array, print it.
The equivalent with grep:
grep -vxF -f /tmp/excludeList /tmp/includeList | while IFS= read -r line; do
[[ -n "$line" ]] && printf "%s\t%s\n" "$ipList" "$line"
done > /tmp/ipList