Pattern: Use of UTF-8 BOM for shell script
Issue: -
Some editors may save a file with a Byte Order Mark to mark the file as UTF-8. Shells do not understand this and will give errors on the first line:
$ bash somescript
somescript: line 1: #!/bin/sh: No such file or directory
$ dash somescript
somescript: 1: somescript: #!/bin/sh: not found
To fix it, remove the byte order mark. One way of doing this is LC_CTYPE=C sed '1s/^...//' < yourscript.
Example of incorrect code:
This is an encoding error that can't be seen in the script itself, but cat -v will show three bytes of garbage at the start of the file:
$ cat -v file
M-oM-;M-?#!/bin/bash
echo "hello world"
Example of correct code:
The code is correct when this garbage does not appear.