Why does a script without she-bang can be run?

Question

As far as I understand, to make kernel execve a non-ELF file, the file must be a script started with a she-bang #!, but I have a script run successfully without it, why does this happen?

xtricman⚓ArchVirtual⏺️~ls a.sh -l
-r-xr-xr-x 1 xtricman users 23 9月  26 18:45 a.sh
xtricman⚓ArchVirtual⏺️~cat a.sh
echo "FDHDSFHGFKJJHGO"
xtricman⚓ArchVirtual⏺️~./a.sh
FDHDSFHGFKJJHGO

This a.sh script doesn't contain a she-bang, so how does it run?

Your current shell interprets it. – Ipor Sircer Sep 27 '18 at 01:31 — Ipor Sircer, Sep 27 '18 at 01:31

score 4 · Accepted Answer · answered Sep 27 '18 at 01:42

4

If the file does not start with a "shebang" line, most shells will attempt to execute the lines in the file themselves.

answered Sep 27 '18 at 01:42

DopeGhoti

76,081

Can I disable this behavior of bash? – 炸鱼薯条德里克 Sep 27 '18 at 02:07
1

The shell will only do this on files marked "executable". If you don't want to execute the file then remove the x flag (chmod a-x a.sh) – Stephen Harris Sep 27 '18 at 02:41

Why does a script without she-bang can be run?

1 Answers1