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'
Related
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 $1}' file.txt
foo
x
So, unless you want to call some external command while looping the file, awk (or sed) is better.
I am trying to run this command:
./smstocurl SLASH2.911325850268888.911325850268896
smstocurl script:
#SLASH2.911325850268888.911325850268896
model=$(echo \&model=$1 | cut -d'.' -f 1)
echo $model
imea1=$(echo \&simImea1=$1 | cut -d'.' -f 2)
echo $imea1
imea2=$(echo \&simImea2=$1 | cut -d'.' -f 3)
echo $imea2
echo $model$imea1$imea2
Result Received
&model=SLASH2911325850268888911325850268896
Result Expected
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
What am I missing here ?
You are cutting based on the dot .. In the first case your desired string contains the first string, the one containing &model, so then it is printed.
However, in the other cases you get the 2nd and 3rd blocks (-f2, -f3), so that the imea text gets cutted off.
Instead, I would use something like this:
while IFS="." read -r model imea1 imea2
do
printf "&model=%s&simImea1=%s&simImea2=%s\n" $model $imea1 $imea2
done <<< "$1"
Note the usage of printf and variables to have more control about what we are writing. Using a lot of escapes like in your echos can be risky.
Test
while IFS="." read -r model imea1 imea2; do printf "&model=%s&simImea1=%s&simImea2=%s\n" $model $imea1 $imea2
done <<< "SLASH2.911325850268888.911325850268896"
Returns:
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
Alternatively, this sed makes it:
sed -r 's/^([^.]*)\.([^.]*)\.([^.]*)$/\&model=\1\&simImea1=\2\&simImea2=\3/' <<< "$1"
by catching each block of words separated by dots and printing back.
You can also use this way
Run:
./program SLASH2.911325850268888.911325850268896
Script:
#!/bin/bash
String=`echo $1 | sed "s/\./\&simImea1=/"`
String=`echo $String | sed "s/\./\&simImea2=/"`
echo "&model=$String
Output:
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
awk way
awk -F. '{print "&model="$1"&simImea1="$2"&simImea2="$3}' <<< "SLASH2.911325850268888.911325850268896"
or
awk -F. '$0="&model="$1"&simImea1="$2"&simImea2="$3' <<< "SLASH2.911325850268888.911325850268896"
output
&model=SLASH2&simImea1=911325850268888&simImea2=911325850268896
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
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'$' -f2,3,4 >> file.txt
done
This is also more portable since the '<<<' operator for here-strings is not POSIX.
This question already has answers here:
How to concatenate multiple lines of output to one line?
(12 answers)
Closed 4 years ago.
I have a file csv :
data1,data2,data2
data3,data4,data5
data6,data7,data8
I want to convert it to (Contained in a variable):
variable=data1,data2,data2%0D%0Adata3,data4,data5%0D%0Adata6,data7,data8
My attempt :
data=''
cat csv | while read line
do
data="${data}%0D%0A${line}"
done
echo $data # Fails, since data remains empty (loop emulates a sub-shell and looses data)
Please help..
Simpler to just strip newlines from the file:
tr '\n' '' < yourfile.txt > concatfile.txt
In bash,
data=$(
while read line
do
echo -n "%0D%0A${line}"
done < csv)
In non-bash shells, you can use `...` instead of $(...). Also, echo -n, which suppresses the newline, is unfortunately not completely portable, but again this will work in bash.
Some of these answers are incredibly complicated. How about this.
data="$(xargs printf ',%s' < csv | cut -b 2-)"
or
data="$(tr '\n' ',' < csv | cut -b 2-)"
Too "external utility" for you?
IFS=$'\n', read -d'\0' -a data < csv
Now you have an array! Output it however you like, perhaps with
data="$(tr ' ' , <<<"${data[#]}")"
Still too "external utility?" Well fine,
data="$(printf "${data[0]}" ; printf ',%s' "${data[#]:1:${#data}}")"
Yes, printf can be a builtin. If it isn't but your echo is and it supports -n, use echo -n instead:
data="$(echo -n "${data[0]}" ; for d in "${data[#]:1:${#data[#]}}" ; do echo -n ,"$d" ; done)"
Okay, now I admit that I am getting a bit silly. Andrew's answer is perfectly correct.
I would much prefer a loop:
for line in $(cat file.txt); do echo -n $line; done
Note: This solution requires the input file to have a new line at the end of the file or it will drop the last line.
Another short bash solution
variable=$(
RS=""
while read line; do
printf "%s%s" "$RS" "$line"
RS='%0D%0A'
done < filename
)
awk 'END { print r }
{ r = r ? r OFS $0 : $0 }
' OFS='%0D%0A' infile
With shell:
data=
while IFS= read -r; do
[ -n "$data" ] &&
data=$data%0D%0A$REPLY ||
data=$REPLY
done < infile
printf '%s\n' "$data"
Recent bash versions:
data=
while IFS= read -r; do
[[ -n $data ]] &&
data+=%0D%0A$REPLY ||
data=$REPLY
done < infile
printf '%s\n' "$data"
A very simple single-line solution which requires no extra files as its quite easy to understand (I think, just cat the file together and perform sed-replace):
output=$(echo $(cat ./myFile.txt) | sed 's/ /%0D%0A/g')
Useless use of cat, punished! You want to feed the CSV into the loop
while read line; do
# ...
done < csv