Handy bash utilities.

utils.sh

# Prints msec in format "[d days ]hh:mm:ss.SSS"
function format_duration #(msec=0)
{
    local t=${1:-0}
    local days=$((t/60/60/24))
    [ $days -gt 0 ] && echo -ne "$days days "
    printf "%d:%02d:%02d" $((t/60/60%24)) $((t/60%60)) $((t%60))
}

# Prints file permissions in decimal mode, ex. 755.
# $ perm ~
# $ 750
function perm #(path=.)
{
    [ -e "${1:-.}" ] && stat -c %a "${1:-.}"
}

# Prints timestamp of elderly modified file matching mask in provided directory.
# If directory does not exist or no files matching mask present then nothing is output.
function eldest_content_mod_ts #(path=., filename_mask=.*)
{
    #if [ -n "`basename '$1'`" ]; then
    if [ -d "${1:-.}" ]; then

        #find "`dirname '$1'`" -type f -maxdepth 1 -name "`basename '$1'`" -printf "%C@ %T@ %P\n"
        
        find "${1:-.}" -maxdepth 1 -name "${2:-.*}" -printf "%C@ %T@ %P\n" \
            | awk '{ print ($1>$2?$1:$2) }' \
            | sort -bgk 1 \
            | tail -n 1

    fi
}

# Prints names of files which match.
# perm - exact match
# -perm - greater or equal
# +perm - less or equal
function match_perm #(filename_mask, perm)
{
    find "`dirname $1`" -maxdepth 1 -name "`basename $1`" -printf "%P\n" -perm +`printf %03d "${2:-0}"`
}

# Prints directory content age in msec.
function content_age #(path=., filename_mask=.*)
{
    local mod_ts="`eldest_content_mod_ts \"$1\" \"$2\"`"
    if [ -n "$mod_ts" ]; then
        expr "`date +%s` - $mod_ts"
    fi
}

# Returns 0 iff provided path is mounted, otherwhise 1.
function mounted #(path=.)
{
    [ -d "${1:-.}" ] && [[ ! `stat -f -L -c %T "${1:-.}"` =~ "ext.*" ]] && return 0
    return 1
}

# Returns 0 iff permissions for path are greater or equal to perm.
function enough_perm #(path, perm)
{
    local act=`perm "$1"`
    local exp=`printf %03d "${2:-0}"`
    [ "${act:0:1}" -ge "${exp:0:1}" ] && [ "${act:1:1}" -ge "${exp:1:1}" ] && [ "${act:2:1}" -ge "${exp:2:1}" ] && return 0
    return 1
}