Joining 2 variables under loop - bash

I'm trying to join 2 variables under loop but I cant get it to work..
My script lists newly added movies. I'm trying to make an output in excel that is clickable. Long story short, I need the script to list the 2 variables like this:
ab
ab
Right now it's doing this
a
a
b
b
This is the code
NEW_MOVIES_DIRLIST=''
for i in $(seq 1 ${NEW_MOVIES_COUNT}); do
MOVIE_PATH=$(echo -e "${NEW_MOVIES_LIST}" | sed -n "${i}p")
NEW_MOVIES_DIRLIST+="$(dirname "${MOVIE_PATH}")/\n"
done
LINKNAME=$(echo -e "${NEW_MOVIES_DIRLIST}" | sed -r 's,FOLTERS_TO_BE_SCANNED/HDD-EXTENDED.-SD./,,g')
NEW_MOVIES_DIRLIST=$(echo -e "${NEW_MOVIES_DIRLIST}" | sed '/^$/d')
NEW_MOVIES_COUNT=$(echo "${NEW_MOVIES_DIRLIST}" | wc -l)
NEW_MOVIES_LIST=''
for ((i = 0; i < ${NEW_MOVIES_COUNT}; i++))
do echo ${NEW_MOVIES_DIRLIST}${LINKNAME}
done
echo "Found ${NEW_MOVIES_COUNT} movies and ${NEW_SERIALS_COUNT} serials!"
${NEW_MOVIES_LIST}
The 2 variables are NEW_MOVIES_DIRLIST and LINKNAME, I can't join them when I run it. Any idea why?

You are adding a newline to the end of the string in the sed. So strip the newline before you display it.
newline=$'\n'
echo "${NEW_MOVIES_DIRLIST//$newline//}$LINKNAME"

Related

Bash: Two "cut" functions in while-loop, only one effective

in a cygwin environment i want to read a csv line for line, and try to get the values from two columns.
So i have
while read line ; do echo `cut -d";" -f5`; done < allk.lst
and the right values are shown.
But:
while read line ; do echo `cut -d";" -f5`; echo `cut -d";" -f4`; done < allk.lst
again shows the values as before...
Any hints to show both values?
Thanks, Bommel
cut -f accepts a list of fields, so there no need to call cut twice
Using cut command to remove multiple columns
echo cut -d";" -f5; does not do what you'd expect. At first, the variable line is missing.
After applying those fixes, you command would look something like:
while read line; do echo $line | cut -d";" -f4-5 ; done < test.txt
Try a demo online!
Hmmm, thanks at first.
Some curiosity:
When using
$ time while read line; do echo $line | cut -d";" -f4-5 ; done < allk.txt
K700W1666;S728A0103
K700W1651;S727A7570
K700W1654;S727A7579
K700W1657;S727A7581
K700W1660;S727A7582
K700W3040;S728A0099
K700W3043;S728A0107
K700W3042;S732A4280
K700W3594;S724A5213
K700W3600;S727A7609
K700W3603;S727A7615
K700W3597;S727A7617
K700W3604;S727A7589
K700W3624;S728A1599
K700W2164;S728A0091
K700W2165;S728A0110
K700W3565;S727A7577
K700W3568;S727A7578
K700W3560;S725A4806
K700W3563;S725A8285
K700W3559;S726A1925
K700W3562;S728A0197
K700W2016;S726A1929
K700W2012;S725A5172
K700W2015;S728A0056
K700W2014;S728A0061
K700W2017;S728A0067
real 0m12.165s
user 0m0.482s
sys 0m1.390s
it takes 12 seconds, and there is a semicolon between.
Whereas
$ time while read line; do echo `cut -d";" -f4-5` ; done < allk.txt
K700W1651;S727A7570 K700W1654;S727A7579 K700W1657;S727A7581 K700W1660;S727A7582 K700W3040;S728A0099 K700W3043;S728A0107 K700W3042;S732A4280 K700W3594;S724A5213 K700W3600;S727A7609 K700W3603;S727A7615 K700W3597;S727A7617 K700W3604;S727A7589 K700W3624;S728A1599 K700W2164;S728A0091 K700W2165;S728A0110 K700W3565;S727A7577 K700W3568;S727A7578 K700W3560;S725A4806 K700W3563;S725A8285 K700W3559;S726A1925 K700W3562;S728A0197 K700W2016;S726A1929 K700W2012;S725A5172 K700W2015;S728A0056 K700W2014;S728A0061 K700W2017;S728A0067
real 0m0.308s
user 0m0.015s
sys 0m0.030s
takes only 0.3 sec... but also with a semic.
So: what is the best way to read this values in two variables (for building SQL commands)?

Loop Script from Input File

I have a reference file with device names in them. For example WABEL8499IPM101. I'm using this script to set the base name (without the last 3 digits) to look at the reference file and see what is already used. If 101 is used it will create a file for me with 102, 103 if I request 2 total. I'm looking to use an input file to run it multiple times. I'm also trying to figure out how to start at 101 if there isn't a name found when searching the reference file
I would like to loop this using an input file instead of manually entering bash test.sh WABEL8499IPM 2 each time. I would like to be able to build an input file of all the names that need compared and then output. It would also be nice that if there isn't a match that it starts creating names at WABEL8499IPM101 instead of just WABEL8499IPM1.
Input file example:
ColumnA (BASE NAME) ColumnB (QUANTITY)
WABEL8499IPM 2
Script:
SRCFILE="~/Desktop/deviceinfo.csv"
LOGDIR="~/Desktop/"
LOGFILE="$LOGDIR/DeviceNames.csv"
# base name, such as "WABEL8499IPM"
device_name=$1
# quantity, such as "2"
quantityNum=$2
# the largest in sequence, such as "WABEL8499IPM108"
max_sequence_name=$(cat $SRCFILE | grep -o -e "$device_name[0-9]*" | sort --reverse | head -n 1)
# extract the last 3digit number (such as "108") from max_sequence_name
max_sequence_num=$(echo $max_sequence_name | rev | cut -c 1-3 | rev)
# create new sequence_name
# such as ["WABEL8499IPM109", "WABEL8499IPM110"]
array_new_sequence_name=()
for i in $(seq 1 $quantityNum);
do
cnum=$((max_sequence_num + i))
array_new_sequence_name+=($(echo $device_name$cnum))
done
#CODE FOR CREATING OUTPUT FILE HERE
#for fn in ${array_new_sequence_name[#]}; do touch $fn; done;
# write log
for sqn in ${array_new_sequence_name[#]};
do
echo $sqn >> $LOGFILE
done
Usage:
bash test.sh WABEL8499IPM 2
Result in the log file:
WABEL8499IPM109
WABEL8499IPM110
Just wrap a loop around your code instead of assuming the args come in on the command line.
SRCFILE="~/Desktop/deviceinfo.csv"
LOGDIR="~/Desktop/"
LOGFILE="$LOGDIR/DeviceNames.csv"
while read device_name quantityNum
do max_sequence_name=$( grep -o -e "$device_name[0-9]*" $SRCFILE |
sort --reverse | head -n 1)
max_sequence_num=${max_sequence_name: -3}
array_new_sequence_name=()
for i in $(seq 1 $quantityNum)
do cnum=$((max_sequence_num + i))
array_new_sequence_name+=("$device_name$cnum")
done
for sqn in ${array_new_sequence_name[#]};
do echo $sqn >> $LOGFILE
done
done < input.file
I'd maybe pass the input file as the parameter now.

How to properly use the grep command to grab and store integers?

I am currently building a bash script for class, and I am trying to use the grep command to grab the values from a simple calculator program and store them in the variables I assign, but I keep receiving a syntax error message when I try to run the script. Any advice on how to fix it? my script looks like this:
#!/bin/bash
addanwser=$(grep -o "num1 + num2" Lab9 -a 5 2)
echo "addanwser"
subanwser=$(grep -o "num1 - num2" Lab9 -s 10 15)
echo "subanwser"
multianwser=$(grep -o "num1 * num2" Lab9 -m 3 10)
echo "multianwser"
divanwser=$(grep -o "num1 / num2" Lab9 -d 100 4)
echo "divanwser"
modanwser=$(grep -o "num1 % num2" Lab9 -r 300 7)
echo "modawser"`
You want to grep the output of a command.
grep searches from either a file or standard input. So you can say either of these equivalent:
grep X file # 1. from a file
... things ... | grep X # 2. from stdin
grep X <<< "content" # 3. using here-strings
For this case, you want to use the last one, so that you execute the program and its output feeds grep directly:
grep <something> <<< "$(Lab9 -s 10 15)"
Which is the same as saying:
Lab9 -s 10 15 | grep <something>
So that grep will act on the output of your program. Since I don't know how Lab9 works, let's use a simple example with seq, that returns numbers from 5 to 15:
$ grep 5 <<< "$(seq 5 15)"
5
15
grep is usually used for finding matching lines of a text file. To actually grab a part of the matched line other tools such as awk are used.
Assuming the output looks like "num1 + num2 = 54" (i.e. fields are separated by space), this should do your job:
addanwser=$(Lab9 -a 5 2 | awk '{print $NF}')
echo "$addanwser"
Make sure you don't miss the '$' sign before addanwser when echo'ing it.
$NF selects the last field. You may select nth field using $n.

for loop control in bash using a string

I want to use a string to control a for loop in bash. My first test code produces what I would expect and what I want:
$ aa='1 2 3 4'
$ for ii in $aa; do echo $ii; done
1
2
3
4
I'd like to use something like the following instead. This doesn't give the output I'd like (I can see why it does what it does).
$ aa='1..4'
$ for ii in $aa; do echo $ii; done
1..4
Any suggestions on how I should modify the second example to give the same output as the first?
Thanks in advance for any thoughts. I'm slowly learning bash but still have a lot to learn.
Mike
The notation could be written out as:
for ii in {1..4}; do echo "$ii"; done
but the {1..4} needs to be written out like that, no variables involved, and not as the result of variable substitution. That is brace expansion in the Bash manual, and it happens before string expansions, etc. You'll probably be best off using:
for ii in $(seq 1 4); do echo "$ii"; done
where either the 1 or the 4 or both can be shell variables.
You could use seq command (see man seq).
$ aa='1 4'
$ for ii in $(seq $aa); do echo $ii; done
Bash won't do brace expansion with variables, but you can use eval:
$ aa='1..4'
$ for ii in $(eval echo {$aa}); do echo $ii; done
1
2
3
4
You could also split aa into an array:
IFS=. arr=($aa)
for ((ii=arr[0]; ii<arr[2]; ii++)); do echo $ii; done
Note that IFS can only be a single character, so the .. range places the numbers into indexes 0 and 2.
Note There are certainly more elegant ways of doing this, as Ben Grimm's answer, and this is not pure bash, as uses seq and awk.
One way of achieving this is by calling seq. It would be trivial if you knew the numbers in the string beforehand, so there would be no need to do any conversion, as you could simple do seq 1 4 or seq $a $b for that matter.
I assume, however, that your input is indeed a string in the format you mentioned, that is, 1..4 or 20..100. For this purpose you could convert the string into 2 numbers ans use them as parameters for seq.
One of possibly many ways of achieving this is:
$ `echo "1..4" | sed -e 's/\.\./ /g' | awk '{print "seq", $1, $2}'`
1
2
3
4
Note that this will work the same way for any input in the given format. If desired, sed can be changed by tr with similar results.
$ x="10..15"
$ `echo $x | tr "." " " | awk '{print "seq", $1, $2}'`
10
11
12
13
14
15

BASH: Iterating two v ariables in a for loop

I am having two files numbers.txt(1 \n 2 \n 3 \n 4 \n 5 \n) and alpha.txt (a \n n \n c \n d \n e \n)
Now I want to iterate both the files at the same time something like.
for num in `cat numbers.txt` && alpha in `cat alpha.txt`
do
echo $num "blah" $alpha
done
Or other idea I was having is
for num in `cat numbers.txt`
do
for alpha in `cat alpha.txt`
do
echo $num 'and' $alpha
break
done
done
but this kind of code always take the first value of $alpha.
I hope my problem is clear enough.
Thanks in advance.
Here it is what I actually intended to do. (Its just an example)
I am having one more file say template.txt having content.
variable1= NUMBER
variable2= ALPHA
I wanted to take the output from two files i.e numbers.txt and alpha.txt(one line from both at a time) and want to replace the NUMBER and ALPHA with the respective content from those two files.
so here it what I did as i got to know how to iterate both files together.
paste number.txt alpha.txt | while read num alpha
do
cp template.txt temp.txt
sed -i "{s/NUMBER/$num/g}" temp.txt
sed -i "{s/ALPHA/$alpha/g}" temp.txt
cat temp.txt >> final.txt
done
Now what i am having in final.txt is:
variable1= 1
variable2= a
variable1= 2
variable2= b
variable1= 3
variable2= c
variable1= 4
variable2= d
variable1= 5
variable2= e
variable1= 6
variable2= f
variable1= 7
variable2= g
variable1= 8
variable2= h
variable1= 9
variable2= i
variable1= 10
variable2= j
Its very simple and stupid approach. I wanted to know is there any other way to do this??
Any suggestion will be appreciated.
No, your question isn't clear enough. Specifically, the way you wish to iterate through your files is unclear, but assuming you want to have an output such as:
1 blah a
2 blah b
3 blah c
4 blah d
5 blah e
you can use the paste utility, like this:
paste number.txt alpha.txt | while read alpha num ; do
echo "$num and $alpha"
done
or even:
paste -d# alpha num | sed 's/#/ blah /'
Your first loop is impossible in bash. Your second one, without the break, would combine each line from numbers.txt with each line from alpha.txt, like this:
1 AND a
1 AND n
1 AND c
...
2 AND a
...
3 AND a
...
4 AND a
...
Your break makes it skip all lines from the alpha.txt, except the 1st one (bmk has already explained it in his answer)
It should be possible to organize the correct loop using the while loop construction, but it would be rather ugly.
There're lots of easier alternatives which maybe a better choice, depending on specifics of your task. For example, you could try this:
paste numbers.txt alpha.txt
or, if you really want your "AND"s, then, something like this:
paste numbers.txt alpha.txt | sed 's/\t/ AND /'
And if your numbers are really sequential (and you can live without 'AND'), you can simply do:
cat -n alpha.txt
Here is an alternate solution according to the first model you suggested:
while read -u 5 a && read -u 6 b
do
echo $a $b
done 5<numbers.txt 6<alpha.txt
The notation 5<numbers.txt tells the shell to open numbers.txt using file descriptor 5. read -u 5 a means read from a value for a from file descriptor 5, which has been associated with numbers.txt.
The advantage of this approach over paste is that it gives you fine-grain control over how you merge the two files. For example you could read one line from the first file and twice from the second file.
In your second example the inner loop is executed only once because of the break. It will simply jump out of the loop, i.e. you will always only get the first element of alpha.txt. Therefore I think you should remove it:
for num in `cat numbers.txt`
do
for alpha in `cat alpha.txt`
do
echo $num 'and' $alpha
done
done
If multiple loop isn't specifically your requirement but getting corresponding lines is then you may try the following code:
for line in `cat numbers.txt`
do
echo $line "and" $(cat alpha.txt| head -n$line | tail -n1 )
done
The head gets you the number of lines equal to the value of line and tail gets you the last element.
#tollboy, I think the answer you are looking for is this:
count=1
for item in $(paste number.txt alpha.txt); do
if [[ "${item}" =~ [a-zA-Z] ]]; then
echo "variable${count}= ${item}" >> final.txt
elif [[ "${item}" =~ [0-9] ]]; then
echo "variable${count}= ${item}" >> final.txt
fi
count=$((count+1))
done
When you type paste number.txt alpha.txt in your console, you see:
1 a
2 b
3 c
4 d
5 e
6 f
7 g
8 h
9 i
10 j
From bash's point of view $(paste number.txt alpha.txt) it looks like this:
1 a 2 b 3 c 4 d 5 e 6 f 7 g 8 h 9 i 10 j
So for each item in that list, figure out if it is alpha or numeric, and print it to the output file.
Lastly, increment the count.

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