How to generate multiple lines in a text file?

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1

Hello,
I want to create a file whose content is multiple lines of strings.

The string has the following pattern:

 
aaaa/bbbb/A-B.txt

A is a variable ranges from A1 to A2
B is a variable ranges from B1 to B2

Any ideas?
Thanks.

2

What is your shell?

3

my shell is bash.

4

Please post sample input lines and desired output lines for us to get the exact idea on this.

5

Thanks for replying, samples are

 
aaaa/bbbb/1-1.txt
aaaa/bbbb/1-2.txt
aaaa/bbbb/1-3.txt
aaaa/bbbb/2-1.txt
aaaa/bbbb/2-2.txt
aaaa/bbbb/2-3.txt
6 
for i in 1 2 3
do
   for j in 1 2 3
   do
      echo "aaaa/bbbb/${i}-${j}.txt" >> outputFile
   done
done
7

Thanks for the code, but the variable A I need should be more than 1000. Typing 1000 numbers in the script is not practical.

8 
i=1
j=1

while [ $i -le 1000 ] ; do
     while [ $j -le 3 ] ; do
          echo "aaaa/bbbb/${i}-${j}.txt" >> outputFile
     done
done
10

can you make the variable i be integers between 1 to 1000?
there must be some method.

11

I didn't understand..!! It is considered as an integer only. Have u tried post #8?

12

this result in the bellow lines

 
aaaa/bbbb/1-1.txt
aaaa/bbbb/1-1.txt
aaaa/bbbb/1-1.txt
aaaa/bbbb/1-1.txt
aaaa/bbbb/1-1.txt
......

---------- Post updated at 03:36 AM ---------- Previous update was at 03:33 AM ----------

sorry, when I post this I didn't see post #8.

13

Oh Sorry..!! There was a silly mistake. variable J should be reset in while loop itself.

i=1
while [ $i -le 1000 ] ; do
     j=1
     while [ $j -le 3 ] ; do
          echo "aaaa/bbbb/${i}-${j}.txt" >> outputFile
     done
done
14

still the same result:confused:

15

I think I need to go for a mental checkup. How can I forget to increment the values of i and j by one in the loop. I am sorry. Please find below the correct code.

i=1
while [ $i -le 1000 ] ; do
     j=1
     while [ $j -le 3 ] ; do
          echo "aaaa/bbbb/${i}-${j}.txt" >> outputFile
          j=$((j + 1))
     done
     i=$((i + 1))
done
16 
for ((i=1;i<=1000;i++))
do
   for ((j=1;j<=1000;j++))
   do
      echo "aaaa/bbbb/${i}-${j}.txt" >> outputFile
   done
done
17

This one works, Thank you very much. I used to be familiar with scripting. But I forgot them long time ago.:slight_smile:

---------- Post updated at 04:00 AM ---------- Previous update was at 03:51 AM ----------

Thank you. This can also work. I once used this code, but I didn't know I need doubling the ().

18

How about this:

#!/bin/bash
ASTART=1
AEND=2000
BSTART=1
BEND=2000
for (( a=$ASTART; a <= $AEND; a++ ))
do
    for (( b=$BSTART; b <= $BEND; b++ ))
    do
        echo "aaaa/bbbb/${a}-${b}.txt" >> output.txt
    done
done
19

I thought you wanted the A and B fields to increment. If that's incorrect just change the first part of the echo command.

#!/bin/bash

outfile=test17.out
if [ -e $outfile ]; then
    rm $outfile
fi

aend=100
bend=10
for (( a=1 ; $a <= $aend;  a=$(($a + 1)) )); do
    for (( b=1 ; $b <= $bend;  b=$(($b + 1)) )); do
        afmt=$(printf "%04d" $a)
        bfmt=$(printf "%04d" $b)
        echo "a${afmt}/b${bfmt}/${afmt}-${bfmt}.txt" >> $outfile
    done
done

Output:

a0001/b0001/0001-0001.txt
a0001/b0002/0001-0002.txt
a0001/b0003/0001-0003.txt
a0001/b0004/0001-0004.txt
a0001/b0005/0001-0005.txt
a0001/b0006/0001-0006.txt
a0001/b0007/0001-0007.txt
a0001/b0008/0001-0008.txt
a0001/b0009/0001-0009.txt
a0001/b0010/0001-0010.txt
a0002/b0001/0002-0001.txt
a0002/b0002/0002-0002.txt
a0002/b0003/0002-0003.txt
a0002/b0004/0002-0004.txt
a0002/b0005/0002-0005.txt
a0002/b0006/0002-0006.txt
a0002/b0007/0002-0007.txt
a0002/b0008/0002-0008.txt
a0002/b0009/0002-0009.txt
a0002/b0010/0002-0010.txt
a0003/b0001/0003-0001.txt
....