add use of TMPDIR for temporary dir, if defined

which the added value is X%

README.md

@@ -13,6 +13,8 @@ This wrapper renders `dc` more usable as a command line calculator by:
 - defining commonly used macros for more complex operations
 - saving precision, top of stack, and registers 0 to 9 ("memories")
   from one invocation to the next in the status file `$HOME/.wdcrc`
+- saving last top of stack value in `${TMPDIR:-/tmp}/wdc-$USER` for further direct use
+  (change file name in the source, if desired)
 
 # PREREQUISITES
 
@@ -160,8 +162,10 @@ only at the very end. Otherwise, e.g the `rem` command would first have its
 
 # FILES
 
-The status between invocations is stored in the file `$HOME/.wdcrc` as a
-list of `dc` commands.
+- The status between invocations is stored in the file `$HOME/.wdcrc` as a list of `dc` commands.
+- The last top of stack value is stored in `/tmp/wdc-$USER`.
+
+_These file names can be easily changed at the beginning of the script._
 
 # BUGS
 

wrapdc.sh

@@ -1,8 +1,10 @@
 #!/bin/sh
 # wrapper for dc
-info="wrapper for dc // 2016-11-22 Y.Bonetti // see https://gitlab.com/yargo/wrapdc"
+info="wrapper for dc // 2017-08-31 Y.Bonetti // see https://gitlab.com/yargo/wrapdc"
 # global status file
 statf=$HOME/.wdcrc
+# output file (last stack top)
+outf=${TMPDIR:-/tmp}/wdc-$USER
 # clear state: precision 2, clear stack and reg.0..9
 clstat='2k 0 0 0 0 0 0s00s10s20s30s40s50s60s70s80s9'
 if test ! -r $statf
@@ -17,22 +19,23 @@ fi
 # macros defined as sed patterns
 # (kill all '!' not part of comparison commands, and also comments)
 mcrs='
-s,%t,SAdLA100*SASBLALB/,g;# percent part: X:=100*X/Y, Y kept
-s,%d,SAddLA-_100*SASBLALB/,g;# percent delta: X:=100*(X-Y)/Y, Y kept
-s,%,SAdLA*100/,g;# percentage: X:=X*Y/100, Y kept
+s,%t,S.dL.100*S.S:L.L:/,g;# percent part: X:=100*X/Y, Y kept
+s,%d,S.ddL.-_100*S.S:L.L:/,g;# percent delta: X:=100*(X-Y)/Y, Y kept
+s,%f,S.dl.*100L.-/,g;# percent future: X:=Y*X/(100-X), Y kept
+s,%,S.dL.*100/,g;# percentage: X:=X*Y/100, Y kept
 s,hm,r60*+,g;# hoursminutes: X:=X+Y*60
 s,rem,\%,g;# remainder: X:=Y%X (instead of normal '%' command)
 s,sto\(.\),s\1l\1,g;# sto.: store with copying (i.e keep value on stack)
-s,fact,[SAlA*LA1-d0<B]SBSA1LAlBx0*sBLB+,g;# factorial: X:=X!
+s,fact,[S.l.*L.1-d0<:]S:S.1L.l:x0*s:L:+,g;# factorial: X:=X!
 s,neg,_1*,g;# negate: X:=-X
-s,inv,1r/,g;# inverse: X:=1/X
-s,\$m,[l4l1/l2l1/]SSl10!=SsSLS,g;# mean value: X:=reg.2/reg.1, Y:=reg.4/reg.1
+s,inv,S.1L./,g;# inverse: X:=1/X
+s,\$m,[l4l1/l2l1/]S.l10!=.s.L.,g;# mean value: X:=reg.2/reg.1, Y:=reg.4/reg.1
 s,\$-,dL2r-s2dd*L3r-s3rdL4r-s4dd*L5r-s5*L6r-s6L11-s1,g;# remove statistic entry
 s,\$+*,dL2+s2dd*L3+s3rdL4+s4dd*L5+s5*L6+s6L11+s1,g;# add statistic entry
 s, , ,;# statistic registers:1=n 2=sumX 3=sumX^2 4=sumY 5=sumY^2 6=sumXY
 s,[eE]\(_*[0-9][0-9]*\), 10 \1^*,g;# infix exponential: X:=X*10^N
 s,drop,0*+,g;# stack drop
-s,r,SRSSLRLS,g;# revert: X:=Y, Y:=X ('r' is a GNU extension)
+s,r,S.S:L.L:,g;# revert: X:=Y, Y:=X ('r' is a GNU extension)
  s,![ 	]*[^<=>].*,,
  s,#.*,,
 '
@@ -96,21 +99,23 @@ l0n[s0
 ]nl8n[s8
 ]nl9n[s9
 ]n
-# clear stack, store 0 in reg.Z and macro in reg.Y, which compares stack
+# clear stack, store 0 in reg.'.' and macro in reg.':', which compares stack
 # depth with 1 (in case of empty stack generated by this '1') and if equal,
-# prints 0 (from reg.Z), else former top of stack, and clears stack
-c 0sZ [1z=Znc]sY
-# apply macro in reg.Y to all saved stack values, and separate with NL
-LElYx[
-]nLDlYx[
-]nLClYx[
-]nLBlYx[
-]nlAlYx[ # ]n
+# prints 0 (from reg.'.'), else former top of stack, and clears stack
+c 0s. [1z=.nc]s:
+# apply macro in reg.':' to all saved stack values, and separate with NL
+LEl:x[
+]nLDl:x[
+]nLCl:x[
+]nLBl:x[
+]nlAl:x[ # ]n
 # print exponentialized version of stack top as comment:
 # A=(number of digits - number of fraction digits - 1) of stack top,
 # divide stack top by 10^A and print, print A
 lA10lAZLAX-1-sAlA^/n[E]nLAp
 ENDOFDCINPUT
+# save stack top in output file for further direct processing
+ tail -n 1 $statf | sed -e 's/ *#.*//' >$outf
 # print stack top
  tail -n 1 $statf
 }