How can I create a Bash script that creates multiple files with text, excluding one? - bash

Question

I need to create Bash script that generates text files named file001.txt through file050.txt
Of those files, all should have this text inserted "This if file number xxx" (where xxx is the assigned file number), except for file007.txt, which needs to me empty.
This is what I have so far..
#!/bin/bash
touch {001..050}.txt
for f in {001..050}
do
echo This is file number > "$f.txt"
done
Not sure where to go from here. Any help would be very appreciated.

Answer 1

#!/bin/bash
for f in {001..050}
do
if [[ ${f} == "007" ]]
then
# creates empty file
touch "${f}.txt"
else
# creates + inserts text into file
echo "some text/file" > "${f}.txt"
fi
done

Answer 2

The continue statement can be used to skip an iteration of a loop and go on to the next -- though since you actually do want to take an operation on file 7 (creating it), it makes just as much sense to have a conditional:
for (( i=1; i<50; i++ )); do
printf -v filename '%03d.txt' "$i"
if (( i == 7 )); then
# create file if it doesn't exist, truncate if it does
>"$filename"
else
echo "This is file number $i" >"$filename"
fi
done
A few words about the specific implementation decisions here:
Using touch file is much slower than > file (since it starts an external command), and doesn't truncate (so if the file already exists it will retain its contents); your textual description of the problem indicates that you want 007.txt to be empty, making truncation appropriate.
Using a C-style for loop, ie. for ((i=0; i<50; i++)), means you can use a variable for the maximum number; ie. for ((i=0; i<max; i++)). You can't do {001..$max}, by contrast. However, this does need meaning to add zero-padding in a separate step -- hence the printf.

Answer 3

Of course, you can costumize the files' name and the text, the key thing is the ${i}. I tried to be clear, but let us know if you don't understand something.
#!/bin/bash
# Looping through 001 to 050
for i in {001..050}
do
if [ ${i} == 007 ]
then
# Create an empty file if the "i" is 007
echo > "file${i}.txt"
else
# Else create a file ("file012.txt" for example)
# with the text "This is file number 012"
echo "This is file number ${i}" > "file${i}.txt"
fi
done