cross-platform-utils.bashlib

# Bash utility functions for BSD (Mac) and GNU (Linux, Mingw, CygWin)
# that shouldn't be necessary to reimplement
#
# We use aliases defined at startup rather than functions to avoid
# repeating the overhead of runtime detection each time a command is invoked
#
# Depends on is_mac from the startup functions

# marker that can be used to avoid re-import
export XPLATFORM_UTILS=1

# to make aliases expand in non-interactive sub-shells
shopt -s expand_aliases

# @returns 0 if running on mac, 1 if not 
function is_mac() {
  local cmd=`which uname`
  if [ -z $cmd ];then
    return 1
  else
    # dynamically redefines the function definition to avoid recomputing 
    if $cmd |grep Darwin 1>/dev/null; then
        is_mac(){ return 0; };
    else 
        is_mac(){ return 1; };
    fi
    is_mac
  fi
}


function is_linux() {
    local cmd=`which uname`
    # no point in checking further if uname is not present
    if [ -z $cmd ];then
        return 1
    fi

    # dynamically redefines the function definition to avoid recomputing
    if [[ $(uname) == "Linux" ]]; then
        is_linux(){ return 0; }
    else
        is_linux(){ return 1; }
    fi
}

# Check if running Windows Subsystem for Linux
# @returns 0 if running WSL, 1 if not
function is_wsl() {
    if ! is_linux;then
        return 1
    fi

    # dynamically redefines the function definition to avoid recomputing
    if uname -a | grep microsoft 1>/dev/null; then
        is_wsl(){ return 0; };
    else
        is_wsl(){ return 1; };
    fi
    is_wsl
}


if ! is_mac; then

    # Interpret regular expressions as extended (modern) regular expressions 
    # rather than basic regular expressions (BRE's).  The re_format(7) manual page fully describes both formats.
    alias util.esed='sed -r '

    # size in bytes
    alias util.size='stat -c %s -- '
else
    alias util.esed='sed -E '
    alias util.size='stat -Lf %z -- '
fi

# vim: ft=sh