How do I use the file redirected to the standard input of a bash script?
$ script.sh < file_to_use_in_script
what do I have to put in my script, so that I can write the filename in a variable from this input, without knowing the pathname beforehand.
FILENAME=$file_to_use_in_script
You can use the filename /dev/stdin. Make sure to only read it once.
$ cat myscript
#!/bin/bash
file=${1:-/dev/stdin}
echo "Reading from $file"
nl "$file"
$ cat myfile
hello world
$ ./myscript myfile
Reading from myfile
1 hello world
$ ./myscript < myfile
Reading from /dev/stdin
1 hello world
$ echo "something" | ./myscript
Reading from /dev/stdin
1 something
i would suggest to pass the filename as a an argument, you obviously know it anyway
echo "name $1"
while read line
do
echo $line
done
and then:
./test.sh foo/bar.txt < foo/bar.txt
gives
name foo/bar.txt
1
2
3
if foo/bar.txt contains 1 2 3
