function parse_dir {
# Syntax:   parse_dir <dir> <dir_struct> [<patch1 ... patchN>]
#       $1:     directory to parse
#       $2:     directory structure
#      [$3...]: <dset>:<var>=<val> patches
# Purpose: parse directory <dir> with structure <dir_struct> and export all variables.
# If $dataset = $dset, the value of <var> obtain with parsing is replaced with <val>.
  local d s
  d=$1; shift; s=$1; shift
  while :; do
    $(eval echo "export ${s%%/*}=${d%%/*}")
    s=${s#*/}; d=${d#*/}
    if [ "$s" = "${s#*/}" ]; then break; fi
  done
  while [ $# -ge 1 ]; do if [ $dataset = ${1%:*} ]; then eval export ${1#*:}; fi; shift; done
  unset d s
}
#==================================================================================
function replace_1 {
  # $1: string  $2: <patch>=<replacement string>
  local out=$1
  while [ "${out%${2%=*}*}" != "$out" ]; do out=${out%${2%=*}*}"${2#*=}"${out##*${2#=*}*}; done
  echo $out; unset out; return 0
}
#==================================================================================
function replace {
  # same as "replace_1", but with several <patch>=<replacement string> arguments.
  local out=$1; shift
  while [ $# -ne 0 ]; do out=$(replace_1 $out "$1"); shift; done
  echo $out; unset out; return 0
}
#==================================================================================
function addc {
  local s="$1"; while [ ${#s} -lt $2 ]; do s="_$s"; done ; echo "$s"; unset s
}
#==================================================================================
function progress_bar {
# $1: iteration  $2: iterations number  $3: length of the bar
  local n bar
  bar=`echo "scale=1 ; (100*$1)/$2" | bc`
  bar="`addc "$bar" 5`% ["
  n=`echo "scale=0 ; ($3*$1)/$2" | bc`
  if [ $n -ne 0 ]; then bar="$bar"`eval "printf '='%.0s {1..$n}"`; fi
  n=$(($3-$n))
  if [ $n -ne 0 ]; then bar="$bar"`eval "printf '.'%.0s {1..$n}"`']\r'; fi
  echo -ne $bar; if [ $2 -eq $1 ]; then echo; fi
  unset n bar
}
#==================================================================================
function extract {
# Input arguments:
#    $1: v_in,v_ou     (input/output variable names)
#    $2: f_in,f_ou     (input/output files names)
#    $3: Ymin,Ymax,dY  (min/max available years, years/file number)
#    $4: nmrg          (number of additional months before and after)
#
# Purpose:
#  * Extract year $Y for variable $v_in from files $f_in containing data from
#    $Ymin to $Ymax, where each input file contains $dY years
#  * Outputs are stored in file $f_ou, and variable renamed $v_ou.
#  * Optionally, add before/after the 12 months the $nmrg previous/next months.
#    - Y=Ymin (missing Ymin-1) => $nmrg last  months of year $Y used instead.
#    - Y=Ymax (missing Ymax+1) => $nmrg first months of year $Y used instead.
#
# Remark:  First record of first file has to be january $Ymin.
#
  local v_in v_ou d_in f_ou Ymin Ymax Yb Ye Y dY nbm nmrg it fin fou fm ff fp ib ie
  v_in="${1%%,*}"; v_ou="${1#*,}"; shift
  f_in="${1%%,*}"; f_ou="${1#*,}"; shift
  Ymin="${1%%,*}"; Ymax="${1#*,}"; dY="${Ymax#*,}"; Ymax="${Ymax%%,*}"; shift
  Y=$1; shift; if [ $# -eq 1 ]; then nmrg=$1; else nmrg=0; fi
  if [ $dY -eq $((Ymax-Ymin+1)) ]; then dY=0; fi    #--- SINGLE FILE
  ff=actu_${v_in}_${Y}.nc; fm=""; fp=""
  #--- INITIAL AND FINAL YEAR OF FILE CONTAINING CURRENT YEAR
  if [ $dY -eq 0 ]; then
    Yb=$Ymin; Ye=$Ymax
  else
    Yb=$((Ymin+dY*((Y-Ymin)/dY))); Ye=$((Yb+dY-1))
    Ye=$(($Ye>$Ymax?$Ymax:$Ye))
  fi
  nbm=$((12*(Ye-Yb+1)-1))                           #--- MONTHS NUMBER OF CURRENT FILE
  it=$((12*(Y-Yb)))                                 #--- JANUARY INDEX IN CURRENT FILE
  fin=`var=$v_in; Yb=$Yb; Ye=$Ye; eval echo $f_in`  #--- CURRENT FILE NAME
  fou=`var=$v_ou; Y=$Y; eval echo $f_ou`            #--- OUTPUT  FILE NAME
  ib=$(($it<=nmrg?0:$((it-nmrg))))                  #--- INDEX OF FIRST USED MONTH
  ie=$(($((it+11+mrg))>=$nbm?$nbm:$((it+11+nmrg)))) #--- INDEX OF LAST USED MONTHF
  rm -f $ff ; rm -f $ff ; ncks -d time,$ib,$ie $fin $ff
  #--- MISSING PREVIOUS YEAR LAST  MONTHS => CURRENT YEAR INSTEAD
  if [ $it           -lt $nmrg ]; then fm="prev_${v_in}_${Y}.nc"; rm -f $fm
    if [[ $Y -eq $Ymin || $dY -eq 0  ]]; then ncks -d time,$((it-nmrg+12)),11 $fin $fm
    else Yb=$((dY*((Y-1)/dY))); Ye=$((Yb+dY-1)); Ye=$(($Ye>$Ymax?$Ymax:$Ye))
      ncks -d time,$((12*(Ye-Yb+1)-nmrg+it)),$((12*(Ye-Yb+1)-1)) `var=$v_in; Yb=$Yb; Ye=$Ye; eval echo $f_in` $fm
    fi
  fi
  #--- MISSING FOLLOWING YEAR FIRST MONTHS => CURRENT YEAR INSTEAD
  if [ $((it+nmrg+11)) -gt $nbm ]; then fp="next_${v_in}_${Y}.nc"; rm -f $fp
    if [[ $Y -eq $Ymax || $dY -eq 0  ]]; then ncks -d time,$((nbm-11)),$((it+nmrg-1)) $fin $fp
    else Yb=$((dY*((Y+1)/dY))); Ye=$((Yb+dY-1)); Ye=$(($Ye>$Ymax?$Ymax:$Ye))
      ncks -d time,0,$((nmrg-1)) `var=$v_in; Yb=$Yb; Ye=$Ye; eval echo $f_in` $fp
    fi
  fi
  if [ ! -d ${fou%/*} ]; then mkdir -p ${fou%/*}; fi
  if [[ "$fm" != "" || "$fp" != "" ]]; then
    rm -f $fou ; ncrcat $fm $ff $fp $fou ; rm -f $fm $ff $fp
  else
    mv $ff $fou
  fi
  if [ "$v_in" != "$v_ou" ]; then
    ncrename -v $v_in,$v_ou $fou > /dev/null 2>&1
  fi
}
#==================================================================================
function make_clim {
# Input arguments:
#    $1: variable name   $2: input files name
#    $3: beg-end years   $4: index for january (optional, starting from 0)
#
# Purpose:
#    Create a 12 months climatology for a variable using 1-year monthly files.
#
# Remark:
#    Files with additional months are usable if the index for january is given (default: 0)
#
  local f_ou f0 Yb Ye ib ie M MM
  Yb="${3%%-*}"; Ye="${3#*-}"
  if [ $# -eq 4 ]; then ib=$4; else ib=0; fi; ie=$((ib+11))  #=== INDEX $ib FOR JANUARY
  for M in $(eval echo {$ib..$ie}); do
    MM=$((M+1-ib)); if [ $MM -le 9 ]; then MM=0$MM; fi
    for Y in `eval echo {${Yb}..${Ye}}`; do
      f_ou=$(var=$1; Y=$Y; eval echo $2)
      rm -f ${1}_$Y$MM.nc ; ncks -d time,$M $(var=$1; Y=$Y; eval echo $f_ou) ${1}_$Y$MM.nc
    done
    rm -f ${1}_$MM.nc ; ncra ${1}_????$MM.nc ${1}_$MM.nc ; rm -f ${1}_????$MM.nc
    progress_bar $((M+1-ib)) $((ie-ib+1)) 50
  done
  f_ou=$(var=$1; Y=${Yb}_${Ye}_clim; eval echo $2)
  if [ ! -p ${f_ou%/*} ]; then mkdir -p ${f_ou%/*}; fi
  rm -f $f_ou ; ncrcat ${1}_??.nc $f_ou ; rm -f ${1}_??.nc
  f0=`var=$1; Y='YYYY'; eval echo $2`; f0=$(var=$1; Y='YYYY'; eval echo $f0); f0=${f0##*/}
  ncatted -a comment,global,a,c,"\nClimatology from $Yb to $Ye using file(s) $f0" $f_ou
}
#==================================================================================
function str2ascii() {
  LC_CTYPE=C printf '%d' "'$1"
}

#==================================================================================
function deblank {
#--- REMOVE UNEXPECTED CHARACTERS (IN PARTICULAR THOSE WEIRD ASCII(0) CHARS)
  local a
  a=$1; while [ `str2ascii ${a:0:1}` -lt 32 ]; do a=${a:1:${#a}}; done; echo $a
}

#==================================================================================
function dim_nam {
  #--- GET DIMENSION $2 (X/Y/Z/T) NAME FOR FILE $1
  #--- SPECIAL CASE: RETURN 'Seasons' IF "$2" = "S".
  local a v Units
  case $2 in
    X) Units='degrees_east  degree_east  degree_e degrees_e "degrees east"  "degree east"  degreee degreese' ;;
    Y) Units='degrees_north degree_north degree_n degrees_n "degrees north" "degree north" degreen degreesn' ;;
    Z) Units='pa pascal pascals hpa millibar millibars mbar mbars mb bar bars atm atms atmosphere atmospheres' ;;
    T) Units=' since' ;;
    S) echo Seasons; return 0 ;;
    *) echo "error in dim_nam: unrecognized axis $2"; return 1 ;;
  esac
  for u in $Units; do
    case $2 in
      X|Y|Z) a=`ncdump -h $1 | grep -i ':units = "'"$u"'"'` ;;
      T)     a=`ncdump -h $1 | grep -i $u | grep ':units = "'` ;;
    esac
    if [ "$a" != "" ]; then
      if [ "$2" = "Z" ]; then v=${a%%:*}; v=`deblank $v`
        if [ "`ncdump -h $1 | grep -i "$v($v)"`" != "" ]; then break; fi
      else break
      fi
    fi
  done
  if [[ "$a" = "" && "$2" = "Z" ]]; then a=`ncdump -h $1 | grep -i ':positive = "'`; fi
  if [ "$a" = "" ]; then echo "error in dim_nam: unable to recognize axis $2"; return 1; fi
  echo ${a%%:*}; return 0
}

#==================================================================================
function test_var {
# Input arguments:
#    $1: file name  $2: variable name
  ncdump -h $1 | grep "double $2" > /dev/null; if [ $? -eq 0 ]; then return 0; fi
  ncdump -h $1 | grep "float  $2" > /dev/null; return $?
}
#==================================================================================
function get_boundsvar {
# Input arguments:
#    $1: file name  $2: variable name
  local a=$(ncdump -h $1 | grep -P "\t$2:bounds")
  if [ "$a" != "${a#*\"}" ]; then a=${a#*\"}; echo ${a%\"*}; else echo ""; fi
}
#==================================================================================
function rename_bounds {
# Input arguments:
#    $1: file name  $2: variable name  $3: new variable name
#    returns: $old_var,$old_boundvar,$new_boundvar
  local vin=$(get_boundsvar $1 $2) beg end vou
  if [ "$vin" = "" ]; then return 1; fi
  beg=${vin##*$2}; if [ "$beg" = "$vin" ]; then beg=$vin; fi
  beg=${vin%%$2*}; if [ "$end" = "$vin" ]; then end=$vin; fi
  if [[  "$beg" = ""  &&  "$end" = ""  ]]; then return 1; fi
  vou=$beg$3$end
  echo "$2,$vin,$vou"
}
#==================================================================================
function rename_dims {
# Input arguments:
#    $1: file name  $2...: <axis>:<target_name> (axis=X,Y,Z or T)
#
# Purpose:
#    Rename dimensions, dimensional variables.
#    In case of boundary grid variables with bounds_<variable> names are available,
#    they are renamed together with the corresponding "bounds" attributes.
  local vio f=$1 att="" ren="" nam_in nam_ou
  shift
  while [ $# -ge 1 ]; do
    nam_ou=${1##*:}; nam_in=$(dim_nam $f ${1%:*}); shift
    if [ "$nam_in" != "$nam_ou" ]; then 
      ren="$ren -d $nam_in,$nam_ou -v $nam_in,$nam_ou"
      #--- CHECK WETHER "bounds" ATTRIBUTE IS THERE
      vio="$(rename_bounds $f $nam_in $nam_ou)"
      if [ "$vio" != "" ]; then
        att="$att -a bounds,$nam_ou,m,c,${vio##*,}"; ren="$ren -v ${vio#*,}"
      fi
    fi
  done
  if [ "$ren" != "" ]; then ncrename $ren $f 2>&1 > /dev/null ; fi
  if [ "$att" != "" ]; then ncatted  $att $f 2>&1 > /dev/null ; fi
}
#==================================================================================
function zonal_mean {
# Input arguments:
#    $1: input file  $2: output file
  local tmp=tmp.$$.nc
  if [ ! -d ${2%/*} ]; then mkdir -p ${2%/*}; fi
  ncwa       -a longitude $1 $tmp ; mv $tmp $2    #--- Zonal mean
  ncks -O -x -v longitude $2 $tmp ; mv $tmp $2    #--- Remove longitude
  v="bounds_longitude"; test_var $2 $v            #--- Remove bounds vars
  if [ $? -eq 0 ]; then ncks -O -x -v $v $2 $tmp ; mv $tmp $2; fi
}
#==================================================================================
function get_date {
# Call get_date1 one time each input file.
# $1: varname    $2: datatype    $3: dirin    $4: <dir_in> patch    $5...$N: <files_in>
# [$N+1...]: <dset>:<var>=<val> to overwrite value of variables evaluated from parsing.
  local v_in dtyp d_in dstr f_in Yb Ye St a f first date dates files_in=""
  v_in=$1; shift; dtyp=$1; shift; d_in=$1; shift; dstr=$1; shift; f0=$1
  while [ "$1" = "${1##*=}" ]; do files_in="$files_in $1"; shift; done
  for f_in in $files_in; do date=$(get_date_1 $v_in $dtyp $d_in $dstr $f_in $*)
    if [ $f_in = $f0 ]; then dates=$date; else dates="$dates $date"; fi
  done
  echo $dates
}
#==================================================================================
function get_date_1 {
# Assumes the following filename structure: *_${Yb}*-${Ye}*.* (Yb/e: 4 digits)
# Returns ${FirstYear}-${LastYear}-${IntervalsLengths}
# $1: varname    $2: datatype    $3: dirin    $4: <dir_in> patch    $5: <file_in>
# [$6...]: <dset>:<var>=<val> to overwrite value of variables evaluated from parsing.
  local v_in dtyp d_in d_str f_in Yb Ye St a f first
  v_in=$1; shift; dtyp=$1; shift; d_in=$1; shift; dstr=$1; shift; f_in=$1; shift
  parse_dir $f_in $dstr $*; Yb=1000000; Ye=0; first='t'
  for f in $(var=$v_in; Yb=????; Ye=????; datatype=$dtyp; eval ls $d_in/$f_in); do
    a=${f##*_}; ymn=${a::4}; if [ $ymn -le $Yb ]; then Yb=$ymn; fi
    a=${a##*-}; ymx=${a::4}; if [ $ymx -ge $Ye ]; then Ye=$ymx; fi
    if [ $first != 't' ]; then St=${St}-; fi; first='f'; St=${St}$((ymx-ymn+1))
  done
  echo $Yb-$Ye-$St
}
#==================================================================================
function dim_len {
  local n
  if [ "$2" = "T" ]; then
    n=$(ncdump -h $1 | grep 'UNLIMITED'); n=${n#*// (}; echo ${n% currently*}
  else
    n=$(ncdump -h $1 | grep $2' = '); n=${n#* = }; echo ${n% ;*}
  fi
}
#==================================================================================
function get_grid {
  # $1: filename $2: varname
  X=$(dim_nam $1 X); if [ $? -ne 0 ]; then X=""; else lX=$(dim_len $1 $X); fi
  Y=$(dim_nam $1 Y); if [ $? -ne 0 ]; then Y=""; else lY=$(dim_len $1 $Y); fi
  Z=$(dim_nam $1 Z); if [ $? -ne 0 ]; then Z=""; else lZ=$(dim_len $1 $Z); fi
  T=$(dim_nam $1 T); if [ $? -ne 0 ]; then T=""; else lT=$(dim_len $1  T); fi
  t=$(ncdump -h $1 | grep "double $2")
  if [ $? -ne 0 ]; then t=$(ncdump -h $1 | grep "float $2"); fi
  t=${t##*$2(}; t=${t%)*}; g=""; r=""
  while :; do s=${t##*, }; t=${t%,*}
    case $s in
      $X) g=${g}X; r=${r}x$lX ;;
      $Y) g=${g}Y; r=${r}x$lY ;;
      $Z) g=${g}Z; r=${r}x$lZ ;;
      $T) g=${g}T; r=${r}x$lT ;;
    esac
    if [ "$s" = "$t" ]; then break; fi
  done
  echo $g=${r:1:${#r}}
}
#==================================================================================
function is_int {
 # $1: string to be checked
  set +vx
  if [[ $1 =~ ^[0-9]+$ ]]; then return 0; else return 1; fi
  set -vx
}
#==================================================================================
function remove_version {
 # $1: variable name
  local out=$1
  while `is_int ${out##*-}`; do out=${out%-*}; done; echo $out; return 1
}