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os#

OS detection, shell capability probes and conditional sudo.

Functions#

  • get_os
  • Purpose: Detect the current OS.
  • Returns: linux, mac, windows, or unknown based on $OSTYPE.

  • Notes: matches any linux* - bash reports linux-musl on Alpine and linux-android on Termux, and both are Linux. Reads $OSTYPE defensively, so a caller running under set -u gets unknown rather than an abort.

  • getos

  • Purpose: Alias of get_os (compatibility).

  • is_macos

  • Purpose: Test for macOS.

  • Returns: success when get_os is mac.

  • is_linux

  • Purpose: Test for Linux (glibc, musl or Android).

  • Returns: success when get_os is linux.

  • bash_major

  • Purpose: Print the major version of the running bash (3, 5, ...).

  • Returns: ${BASH_VERSINFO[0]}, or 0 when unset.

  • bash_at_least major [minor]

  • Purpose: Test the running bash against a minimum version.
  • Args:
    • major - required major version.
    • minor - optional minimum minor version (default 0).
  • Returns: success when the running bash is at least that version.

  • Example: bash_at_least 4 || echo "no associative arrays here"

  • require_bash4 feature

  • Purpose: Fail loudly, with an actionable message, when the running bash predates 4.0. On macOS the message names brew install bash.
  • Args:
    • feature - what needs bash 4, named in the error.
  • Returns: 0 on bash 4+, 1 otherwise (logging through log_error when the logging module is loaded, else to stderr).

  • Notes: reserved for the few entry points that genuinely cannot work on bash 3.2 - those taking an associative array from the caller, namely select_distro, select_multiple_distros and download_iso. Everything else in this library runs unchanged on bash 3.2, which is what macOS ships as /bin/bash; using this as a general guard would produce errors a caller cannot act on.

  • is_wsl

  • Purpose: Detect whether script is running in WSL/WSL2.

  • Returns: success when /proc/version includes Microsoft or WSL_DISTRO_NAME is set.

  • run_with_optional_sudo use_sudo_bool command [args...]

  • Purpose: Run a command with sudo when the first argument equals true and sudo exists.
  • Args:
    • use_sudo_bool - true to use sudo if available, anything else to run directly.
    • command [args...] - command to execute.
  • Returns: exit code of the underlying command.