"zsh: permission denied" when running a script: the execute bit, and other causes

1. Look at the permissions

ls -l deploy.sh

-rw-r--r--  1 alex  staff  412 Nov 12 10:00 deploy.sh

There’s no x in -rw-r--r--, so nobody may execute it. Add it for everyone, or just for you:

chmod +x deploy.sh
chmod u+x deploy.sh

-rwxr-xr-x  1 alex  staff  412 Nov 12 10:00 deploy.sh

The chmod Calculator shows what 755, u+x and the others mean, in both directions.

In Git, the execute bit is recorded. If a script loses it after each clone, store it in the repository: git update-index --chmod=+x deploy.sh, then commit.

2. The path is a folder

zsh gives the same message when you try to run a folder:

% /usr/local/bin
zsh: permission denied: /usr/local/bin

Folders do have an x permission, but for a folder it means “may enter”, not “may run”. Check what the path is with ls -ld, and add the program’s name: /usr/local/bin/mytool. To go into the folder, use cd.

A typo in a variable often causes this one. $TOOLS_DIR/mytool with an empty TOOLS_DIR turns into /mytool, and a variable holding just a folder name runs the folder.

3. It’s executable, and still refused

You can’t enter a folder on the way. Every folder in the path needs x for you. ls -ld on each one shows it, and namei -l /path/to/deploy.sh lists them all at once, on Linux.

A disk mounted with noexec. On Linux, /tmp, removable drives and some network shares are often mounted so that nothing on them can run. Check with:

findmnt -T deploy.sh -o TARGET,OPTIONS

Run it with bash deploy.sh, or copy it somewhere else. On macOS, mount shows a similar noexec flag for some network and external volumes.

macOS protections. A script in Desktop, Documents or Downloads, or on an external disk, may need your terminal to have access. That usually gives Operation not permitted rather than this, as explained in Operation not permitted.

4. A different message, after the fix

Once it’s allowed to run, another problem may show up:

zsh: ./deploy.sh: bad interpreter: /bin/bash^M: no such file or directory

The ^M means Windows line endings: see the bad interpreter section of the bash article.

zsh: command not found: deploy.sh

You typed it without ./, so zsh searched your PATH, which doesn’t include the current folder. Use ./deploy.sh.