$ ls /bin/bash* | cat -v
/bin/bash
/bin/bash^M
$ file /bin/bash^M
: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.0.30, dynamically linked (uses shared libs), for GNU/Linux 2.0.30, stripped
$ /bin/bash^M
Your shell script has DOS linefeeds in it!