1# Generate a sequence from m to n, m defaults to 1. 2 3seq () 4{ 5 declare -i lo hi i # makes local 6 local _SEQ INIT COMPARE STEP 7 8 case "$1" in 9 -r) INIT='i=$hi _SEQ=""' COMPARE='let "i >= $lo"' STEP='let i-=1' ; shift ;; 10 *) INIT='i=$lo _SEQ=""' COMPARE='let "i <= $hi"' STEP='let i+=1' ;; 11 esac 12 13 case $# in 14 1) lo=1 hi="$1" ;; 15 2) lo=$1 hi=$2 ;; 16 *) echo seq: usage: seq [-r] [low] high 1>&2 ; return 2 ;; 17 esac 18 19 # equivalent to the as-yet-unimplemented 20 # for (( "$INIT" ; "$COMPARE" ; "$STEP" )); do _SEQ="${_SEQ}$i "; done 21 eval "$INIT" 22 while eval "$COMPARE"; do 23 _SEQ="${_SEQ}$i " 24 eval "$STEP" 25 done 26 echo "${_SEQ# }" 27 return 0 28} 29 30# like the APL `iota' function (or at least how I remember it :-) 31iota() 32{ 33 case $# in 34 1) seq 1 "$1"; return $?;; 35 *) echo "iota: usage: iota high" 1>&2; return 2;; 36 esac 37} 38