permissions to bash file

Make a script executable

1. Add a shebang at top of the file (recommended):

#!/bin/bash

2. Give execute permission:

chmod +x script.sh        # add execute for user/group/others

3. More controlled (common choices):

chmod 755 script.sh       # rwx r-x r-x  -> owner can write; others can read+execute
chmod 700 script.sh       # rwx --- ---  -> only owner can read/write/execute
chmod 744 script.sh       # rwx r-- r--  -> owner write, others read only (but not execute)

Numeric breakdown: r=4, w=2, x=1. Example 755 = 4+2+1 (owner) : 4+1 (group) : 4+1 (others).

Check current permissions

ls -l script.sh
# -rwxr-xr-x 1 prabhu prabhu 409 Jun 1 12:00 script.sh

Run the script

• If executable: ./script.sh

• Without making executable: bash script.sh or sh script.sh

Change owner/group (if needed)

sudo chown user:group script.sh
# e.g.
sudo chown prabhu:prabhu script.sh

Make many scripts executable

chmod +x *.sh

Common gotchas

CRLF line endings (Windows) cause /bin/bash^M: bad interpreter errors — fix with dos2unix script.sh or sed -i 's/\r$//' script.sh.

• If you still get permission denied, check parent directory execute/search bit: you need x on directories to traverse them.

• If script is on a mounted filesystem with noexec option, you cannot execute — run via bash script.sh or remount without noexec.

If you want, tell me:

• the filename and desired access (only you vs everyone), and I’ll give the exact command to run; or

• paste ls -l script.sh output and I’ll interpret it.