# Helper functions to ensure portability and/or provide choices

_seq() (
    # Pure shell counter meant to be used in 'for' loops.
    i=0 buf=''
    while [ "$(( i += 1 ))" -le "$1" ]; do
        buf="$buf $i "
    done
    printf '%s' "$buf"
)

_stat() (
    _user=; eval set -- "$(ls -ld "$1")"
    id -u "${_user:=$3}" >/dev/null 2>&1 || _user=root
    printf '%s' "$_user"
)

sh256() {
    # This is a sha256sum function for outputting a standard
    # hash digest. sha256 on BSD systems require an '-r' flag
    # for outputting the same way with sha256sum, and still,
    # it outputs a single space between the hash and the file
    # whereas sha256sum outputs double spaces. It fallbacks to
    # openssl, but that is rarely ever needed.
    { sha256sum "$1" 2>/dev/null   ||
      sha256 -r "$1" 2>/dev/null   ||
      openssl dgst -r -sha256 "$1" ||
      die "No sha256 program could be run." ;} |

        while read -r hash _; do printf '%s  %s\n' "$hash" "$1"; done
}

decompress() {
    case $1 in
        *.tar)      cat       ;;
        *.bz2)      bzip2 -cd ;;
        *.xz|*.txz) xz -dcT 0 ;;
        *.tgz|*.gz) gzip -cd  ;;
        *.zst)      zstd -cd  ;;
    esac < "$1"
}

as_root() {
    # Simple function to run a command as root using either 'sudo',
    # 'doas' or 'su'. Hurrah for choice.
    [ "$uid" = 0 ] || log "Using '${su:-su}' (to become ${user:=root})"

    # We are exporting package manager variables, so that we still have the
    # same repository paths / access to the same cache directories etc.
    set -- HOME="$HOME" \
           USER="$user" \
           XDG_CACHE_HOME="$XDG_CACHE_HOME" \
           CPT_CACHE="$CPT_CACHE" \
           CPT_CHOICE="$CPT_CHOICE" \
           CPT_COMPRESS="$CPT_COMPRESS" \
           CPT_DEBUG="$CPT_DEBUG" \
           CPT_FETCH="$CPT_FETCH" \
           CPT_FORCE="$CPT_FORCE" \
           CPT_HOOK="$CPT_HOOK" \
           CPT_KEEPLOG="$CPT_KEEPLOG" \
           CPT_PATH="$CPT_PATH" \
           CPT_PID="$CPT_PID" \
           CPT_PROMPT="$CPT_PROMPT" \
           CPT_ROOT="$CPT_ROOT" \
           CPT_TMPDIR="$CPT_TMPDIR" \
           "$@"

    case ${su##*/} in
        sls|sudo|doas) "$su" -u "$user" -- env "$@" ;;
        su)   su -c "env $* <&3" "$user" 3<&0 </dev/tty ;;
        *)    die "Invalid CPT_SU value: $su" ;;
    esac
}

# Local Variables:
# mode: sh
# End: