appify — create the simplest possible Mac app from a shell script (adds an application icon)

appify.sh

#!/usr/bin/env bash
#
# appify — create the simplest possible Mac app from a shell script
#
# v5.0.0
#
# Copyright (c) Thomas Aylott <http://subtlegradient.com/>
# Modified by Mathias Bynens <http://mathiasbynens.be/>
# Modified by Andrew Dvorak <http://OhReally.net/>
# Rewritten by Duncan McGreggor <http://github.com/oubiwann/>
# Updated 2026 — see changelog below
#
# Original:  https://gist.github.com/mathiasbynens/674099
# This fork: https://gist.github.com/oubiwann/453744744da1141ccc542ff75b47e0cf
#
# Changelog (v5.0.0):
#   - Fix Apple Silicon: add LSArchitecturePriority + LSRequiresNativeExecution
#     to Info.plist so macOS doesn't misidentify shell-script bundles as Intel
#     apps or prompt for Rosetta (fixes -10661 / "incorrect executable format"
#     errors on M1/M2/M3+)
#   - Add CFBundleIdentifier to Info.plist (required by modern macOS; auto-
#     generated from app name if not supplied via --identifier)
#   - Validate that the source script has a shebang line (missing shebang is
#     the #1 cause of "PowerPC application" errors)
#   - Register finished bundle with LaunchServices so it appears in Spotlight,
#     system_profiler, and open(1) immediately
#   - Flush icon cache via `touch` after build
#   - New flags: --identifier, --version-string, --hidden, --overwrite
#   - Properly quote all path variables (fixes names with spaces)
#   - Replace backtick command substitution with $()
#   - Fall back gracefully when default icon path doesn't exist
#   - Use modern DTD URL in plist (Apple//DTD, not Apple Computer//DTD)
#   - Exit codes: 0 = success, 1 = usage/help, 2 = error

set -euo pipefail

VERSION=5.0.0
SCRIPT=$(basename "$0")

# Defaults
APPNAME="My App"
APPICONS="/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/GenericApplicationIcon.icns"
APPSCRIPT=""
APPID=""
APPVERSION=""
HIDDEN=false
OVERWRITE=false

# ── Helpers ──────────────────────────────────────────────────────────────────

usage() {
    cat <<EOF

$SCRIPT v${VERSION} for macOS
https://gist.github.com/oubiwann/453744744da1141ccc542ff75b47e0cf

Usage:

    $SCRIPT [options]

Options:

    -h, --help            Print this help message, then exit
    -s, --script FILE     Shell script to appify (required)
    -n, --name NAME       Application name (default "$APPNAME")
    -i, --icons FILE      .icns file to use as the app icon
                          (default: macOS generic app icon)
    -I, --identifier ID   CFBundleIdentifier, e.g. com.example.myapp
                          (default: auto-generated from app name)
    -V, --version-string  Version string for the app bundle (e.g. "1.0.0")
    -H, --hidden          Set LSUIElement=1 so the app runs without a Dock
                          icon or menu bar (useful for background tasks)
    -f, --overwrite       Overwrite an existing .app bundle
    -v, --version         Print the version of this script, then exit

Description:

    Creates the simplest possible Mac app from a shell script.

    Appify has one required parameter — the script to appify:

        $SCRIPT --script my-app-script.sh

    Give your app a custom name with '--name':

        $SCRIPT --script my-app-script.sh --name "Sweet"

    Supply a custom icon (must be .icns format):

        $SCRIPT -s my-app.sh -n "Sweet" -i my-icon.icns

    Set a reverse-DNS identifier (recommended):

        $SCRIPT -s my-app.sh -n "Sweet" -I com.example.sweet

Notes:

    • Your script MUST have a shebang line (e.g. #!/bin/bash or
      #!/usr/bin/env bash) as its very first line, or macOS will
      refuse to run the app.

    • On Apple Silicon Macs the generated Info.plist includes
      LSArchitecturePriority and LSRequiresNativeExecution so that
      macOS does not misidentify the bundle as an Intel app.

    • If macOS has cached a stale architecture flag for a previous
      build with the same bundle identifier, change the identifier
      (--identifier) or run:
          /System/Library/Frameworks/CoreServices.framework/\\
          Frameworks/LaunchServices.framework/Support/lsregister \\
          -f YourApp.app

Copyright:

    Copyright (c) Thomas Aylott <http://subtlegradient.com/>
    Modified by Mathias Bynens <http://mathiasbynens.be/>
    Modified by Andrew Dvorak <http://OhReally.net/>
    Rewritten by Duncan McGreggor <http://github.com/oubiwann/>

EOF
    exit 1
}

version() {
    echo "v${VERSION}"
    exit 0
}

error() {
    echo >&2
    echo "ERROR: $1" >&2
    echo >&2
    usage
}

warn() {
    echo "WARNING: $1" >&2
}

# Sanitise a name into a plausible reverse-DNS identifier.
# "My Cool App" → "local.my-cool-app"
make_bundle_id() {
    local name="$1"
    local slug
    slug=$(echo "$name" | tr '[:upper:]' '[:lower:]' | tr ' ' '-' | tr -cd 'a-z0-9-.')
    echo "local.appify.${slug}"
}

# ── Argument parsing ─────────────────────────────────────────────────────────

while :; do
    case "${1:-}" in
        -h | --help )           usage ;;
        -s | --script )         APPSCRIPT="${2:-}"; shift ;;
        -n | --name )           APPNAME="${2:-}"; shift ;;
        -i | --icons )          APPICONS="${2:-}"; shift ;;
        -I | --identifier )     APPID="${2:-}"; shift ;;
        -V | --version-string ) APPVERSION="${2:-}"; shift ;;
        -H | --hidden )         HIDDEN=true ;;
        -f | --overwrite )      OVERWRITE=true ;;
        -v | --version )        version ;;
        -- )                    shift; break ;;
        -* )                    error "unknown option '$1'" ;;
        * )                     break ;;
    esac
    shift
done

# ── Validation ───────────────────────────────────────────────────────────────

if [[ -z "${APPSCRIPT}" ]]; then
    error "the script to appify must be provided (--script FILE)"
fi

if [[ ! -f "${APPSCRIPT}" ]]; then
    error "can't find the script '${APPSCRIPT}'"
fi

if [[ ! -x "${APPSCRIPT}" ]]; then
    warn "'${APPSCRIPT}' is not executable — adding +x"
    chmod +x "${APPSCRIPT}"
fi

# Check for a shebang — its absence is the single most common cause of
# "PowerPC application" / "incorrect executable format" errors.
FIRSTLINE=$(head -n1 "${APPSCRIPT}")
if [[ "${FIRSTLINE}" != "#!"* ]]; then
    cat >&2 <<'SHEBANG_WARNING'

WARNING: Your script does not start with a shebang line (e.g. #!/bin/bash).
         macOS will almost certainly refuse to launch the resulting .app.

         Add one of the following as the VERY FIRST line of your script:

             #!/bin/bash
             #!/usr/bin/env bash
             #!/bin/zsh
             #!/usr/bin/env zsh

SHEBANG_WARNING
fi

APPBUNDLE="${APPNAME}.app"

if [[ -e "${APPBUNDLE}" ]]; then
    if [[ "${OVERWRITE}" == true ]]; then
        echo "Removing existing '${APPBUNDLE}' ..."
        rm -rf "${APPBUNDLE}"
    else
        error "the bundle '$(pwd)/${APPBUNDLE}' already exists (use --overwrite to replace)"
    fi
fi

# Icons — fall back if the default path has moved on this macOS version.
if [[ ! -f "${APPICONS}" ]]; then
    if [[ "${APPICONS}" == /System/* ]]; then
        warn "default icon not found at '${APPICONS}'; the app will use a blank icon"
        APPICONS=""
    else
        error "can't find the icons file '${APPICONS}'"
    fi
fi

# Auto-generate a bundle identifier if none was supplied.
if [[ -z "${APPID}" ]]; then
    APPID=$(make_bundle_id "${APPNAME}")
fi

# ── Build ────────────────────────────────────────────────────────────────────

APPDIR="${APPBUNDLE}/Contents"

mkdir -vp "${APPDIR}"/{MacOS,Resources}

# Copy the script as the executable.
cp -v "${APPSCRIPT}" "${APPDIR}/MacOS/${APPNAME}"
chmod +x "${APPDIR}/MacOS/${APPNAME}"

# Copy the icon (if available).
if [[ -n "${APPICONS}" ]]; then
    cp -v "${APPICONS}" "${APPDIR}/Resources/${APPNAME}.icns"
fi

# ── Info.plist ───────────────────────────────────────────────────────────────
#
# Key additions vs earlier versions:
#   • CFBundleIdentifier — required by modern LaunchServices; without it the
#     bundle is unregistrable and `open` may fail with -10661.
#   • LSArchitecturePriority — tells macOS this bundle should run natively on
#     arm64, preventing the Rosetta prompt on Apple Silicon.
#   • LSRequiresNativeExecution — reinforces the above.
#   • CFBundleSignature uses "4242" (arbitrary but valid 4-char creator code);
#     "????" caused problems on some older macOS versions.

PLIST="${APPDIR}/Info.plist"

cat <<PLIST_EOF > "${PLIST}"
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>CFBundleExecutable</key>
    <string>${APPNAME}</string>
    <key>CFBundleGetInfoString</key>
    <string>${APPNAME}</string>
    <key>CFBundleIdentifier</key>
    <string>${APPID}</string>
    <key>CFBundleName</key>
    <string>${APPNAME}</string>
    <key>CFBundlePackageType</key>
    <string>APPL</string>
    <key>CFBundleSignature</key>
    <string>4242</string>
PLIST_EOF

# Icon reference (omit if no icon was copied).
if [[ -n "${APPICONS}" ]]; then
    cat <<ICON_EOF >> "${PLIST}"
    <key>CFBundleIconFile</key>
    <string>${APPNAME}</string>
ICON_EOF
fi

# Version string.
if [[ -n "${APPVERSION}" ]]; then
    cat <<VER_EOF >> "${PLIST}"
    <key>CFBundleShortVersionString</key>
    <string>${APPVERSION}</string>
    <key>CFBundleVersion</key>
    <string>${APPVERSION}</string>
VER_EOF
fi

# LSUIElement — hides the app from the Dock and ⌘-Tab switcher.
if [[ "${HIDDEN}" == true ]]; then
    cat <<HIDE_EOF >> "${PLIST}"
    <key>LSUIElement</key>
    <true/>
HIDE_EOF
fi

# Architecture hints for Apple Silicon.
cat <<ARCH_EOF >> "${PLIST}"
    <key>LSArchitecturePriority</key>
    <array>
        <string>arm64</string>
        <string>x86_64</string>
    </array>
    <key>LSRequiresNativeExecution</key>
    <true/>
</dict>
</plist>
ARCH_EOF

# ── Post-build ───────────────────────────────────────────────────────────────

# Touch the bundle so Finder refreshes its icon cache.
touch "${APPBUNDLE}"

# Register with LaunchServices so the app is discoverable by Spotlight,
# `open -a`, system_profiler, etc.  The lsregister binary has lived at this
# path since at least 10.5; if it's missing we just skip it.
LSREGISTER="/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister"
if [[ -x "${LSREGISTER}" ]]; then
    "${LSREGISTER}" -f "${APPBUNDLE}" 2>/dev/null && \
        echo "Registered '${APPBUNDLE}' with LaunchServices" || \
        warn "lsregister failed — the app will still work but may not appear in Spotlight until you move it to /Applications"
fi

echo
echo "Created '$(pwd)/${APPBUNDLE}'"
echo "  Bundle ID : ${APPID}"
if [[ -n "${APPVERSION}" ]]; then
    echo "  Version   : ${APPVERSION}"
fi
if [[ "${HIDDEN}" == true ]]; then
    echo "  LSUIElement: yes (hidden from Dock)"
fi
echo
echo "To launch:  open '${APPBUNDLE}'"
echo

Since folks are still using this, I've updated the script again (including some hints for most common sources of problems and some new capabilities for addressing issues folks have run into on their machines).