用于linux的Bash脚本创建5个新文件

Question

I need help in creating a bash script. I want the script to create 5 new files each time I run it.

I tried a basic for loop like this:

#!/bin/bash

for i in {0..5}
do
  touch File${i}
done

Obviously, it only creates 5 files named File1 to File5 . I need it to make 5 new files with new names each time I run the script. any tips in what direction to look for?

Answer 1

No need to use loop. Simply do this

touch File{1..5}  

To create new files each time based on range

START=$(ls | wc -l)
END=$((START+1))
for((i=START;i<=END;i++)); do  
    touch File$i

Answer 2

This answer was given before it became clear that the names were to be consecutive and following on from the previous run. I will let it stand rather than delete it as it is potentially informative for other, future readers.

How about with mktemp :

mktemp {a..e}XXXXXX

Sample Output

aW1KLgp
bZrPq2I
c1BKn8i
dIjzxrc
ezpWkkO

That will give you one file beginning with a , one beginning with b and so on.

Or you may prefer this:

mktemp {1..5}-XXXXXX
1-00r8Gf
2-wjojeF
3-lPni6G
4-ihYrOP
5-B5YtEB

Answer 3

Try something like:

#!/bin/bash

count=$(ls File* 2>/dev/null | wc -l)
for ((i=$count+1; i<=$count+5; i++)); do
    touch $(printf "File%03d" $i)
done

Explanations:

Here I assume the files start with prefix "File".

The line count=$(ls ...) counts how many files which start with "File" exist in the directory. The part 2>/dev/null works to suppress the error message when there is no such a file on the initial execution. Then the for loop generates additional five files accordingly. You can modify the number in %03d depending on how many files you are going to produce.

Answer 4

While some of the other suggestions use ls piped to wc this isn't guaranteed to be correct, see here.

Instead you can get the number of files in your current directory as such:

files=( * )  
num_files=${#files[@]}  
if [[ $files=='*' ]]; then  
    touch File{000..004}
    exit
fi
for (( i=num_files; i<num_files+5; i++)); do  
    touch $( printf "File%03d" $i )
done

A quick breakdown on what each part does:
files=( * ) Uses pattern matching to get all the files in your current directory, even if they contain newlines. The ( ) means to make an array from those files and assign it to files .

${#files[@]} will give the number of elements in the array files , aka how many files are in your directory.

The if block checks if files is litterally * , which means there were no files to match, aka you were in an empty directory, in which case it will create the first 5 files for you. Otherwise you iterate over the next 5 file numbers.

touch $( printf "File$03d" $i ) executes that printf in a subshell, which will return the name File followed by a 3 digit number with leading zeroes, so that your files will be sorted how you would expect.

Also you were off by one in your question; {0..5} gives you six numbers, not five.

Hope this helps!

Edit 0:

As Mark said below, using shopt -s nullglob will cause the wildcard to return nothing if it doesn't match any files, which is the desired behavior here.

Here's the updated solution:

shopt -s nullglob  
files=( * )  
num_files=${#files[@]}  
for (( i=num_files; i<num_files+5; i++)); do  
    touch $( printf "File%03d" $i )
done