set up new repo

README.md

@@ -1,3 +1,10 @@
 # spacelaunch
 
-Space Launch is a pubnix take on the classic Unix prank called Steam Locomotive.  Rather than running a steam engine train across users' screen when they mistype 'ls' as 'sl', Space Launch blasts a rocket across their screen.  
+Space Launch is a pubnix take on the classic Unix prank called 
+Steam Locomotive.  Rather than running a steam engine train 
+across users' screen when they mistype 'ls' as 'sl', Space 
+Launch blasts a rocket across their screen.
+
+Space Launch is a collaborative pubnix/tilde project.  It was 
+started by cmccabe in 2019, but you are encouraged to improve 
+it.  The code is here: https://tildegit.org/cmccabe/spacelaunch

config

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+##########################################################
+##
+## CONFIGURATION VARIABLES FOR SPACE LAUNCH (SL)
+
+CODE_DIR=/home/cmccabe/code/spacelaunch
+  NOSE_CONE=$CODE_DIR/nose_cone.txt
+  FLAMES=$CODE_DIR/flames.txt
+  KABOOM=$CODE_DIR/kaboom.txt
+
+HOME_DIR=/home # LOCATION OF USERS' HOME DIRECTORIES
+               # E.G. /home WHERE USER DIRECTORIES ARE OF
+               #     THE FORM /home/username
+               # OR, SDF META ARRAY AS AN EXAMPLE, 
+               #      /meta/* WHERE USER DIRS ARE OF THE
+               #     FORM /meta/[a-z]/username
+
+VROOM_WIDTH=22       ## WIDTH OF USER .vroom FILE (MUST BE
+                     ## MATCHED TO WIDTH OF NOSE CONE AND
+                     ## FLAMES).
+VROOM_HEIGHT_MAX=22  ## MAX NUM LINES IN .vroom FILE
+SLEEP_TIME=0.05      ## HOW FAST TO MOVE THE ROCKET.
+ROCKET_SIZE=5        ## MAX NUMBER OF USER ROCKET PARTS TO GRAB.
+
+##
+###########################################################

flames.txt

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+   /           ||           \
+  / |          ||          | \
+ /  |          ||          |  \
+/   |          ||          |   \
+|   |          ||          |   |
+|  / __________||__________ \  |
+| / |__________||__________| \ |
+|/   \         ||         /   \|
+      ))())(()())((())(()(
+     (( (( )) (( ))) (( )))
+     )) )) (( )) ((( )) (((
+     (  (( )  ((  )) (  ))
+      (  ) )) )  ))  ) ))
+       ( ( (( ( )  )) ))
+        ()  )  )  ((  (
+             ((  )  

kaboom.txt

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+              *
+              |
+              .
+        .     |   _    .
+         \         )  /
+          .   ^      . 
+           \ / \    /   -*
+      /   _ .      .
+     <   (   \    /  _  \
+      \       ./\.    )  >
+            ( /  \   \  /
+*----         \  /    >
+         / (   \/ )  /
+        <     .  .     \
+         \   /    \     >  ---*
+      (_    .   _)  . ) /
+           / (_     \
+          .          .
+         /      \ /   \
+        .   /    v     . 
+           .
+          /
+         *

nose_cone.txt

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+          /\
+         /  \
+        /    \
+       /      \
+      /        \
+     /          \
+    /            \
+   /              \
+  /                \
+ /                  \
+/                    \
+======================

sl.sh

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+#!/bin/bash
+
+## SPACE LAUNCH - A multi-user take on the classic Unix 
+##                steam locomotive (sl) prank.
+##                Written by cmccabe on the Zaibatsu in 2019.
+##
+## Questions? Comments? Smart remarks? --> cmccabe@sdf.org
+##
+## System users should create ~/.vroom files that contain lines within
+## the configured limits of length and line numbers.  These .vroom files
+## will be fused together using space-age technology and launched into
+## orbit whenever this script is run.
+## -t, -m and -h switches are explained in the help:
+## > sl.sh -h
+
+#########################################################################
+## CONFIGURATION VARIABLES
+source /home/cmccabe/code/spacelaunch/config
+
+#########################################################################
+## VARIABLE INITIALIZATION AND SET-UP STEPS
+
+# stty -echo ## TO DO: HOW TO RE-ENABLE THIS FROM ^C TRAP FUNCTION?
+#                      OTHERWISE USER CAN'T SEE THEIR CHARS ECHOED
+#                      AFTER THEY KILL THIS SCRIPT.
+ 
+USER=$(id -run)
+
+# HEIGHT OF TERMINAL WINDOW; USED TO PUSH ROCKET OFF THE SCREEN
+TRAILING_SPACE=$(tput lines)
+ALTITUDE=0
+
+ROCKET_PARTS=$(ls $HOME_DIR/*/.vroom | shuf -n $ROCKET_SIZE)
+ROCKET_PARTS=(${ROCKET_PARTS[@]})
+[ ${#ROCKET_PARTS[@]} -gt $ROCKET_SIZE ] && ROCKET_PARTS=(${ROCKET_PARTS[@]:1:${ROCKET_SIZE}})
+# ^^ CHOOSE $ROCKET_SIZE RANDOM FILES FROM ALL ~.vroom FILES
+
+read -r -d '' HELP_TEXT << EOM
+
+================= SPACE LAUNCH (sl) HELP =================
+
+Space Launch reads everyone's ~/.vroom file and concatenates
+a random selection of them into an animated rocket.
+
+You can create your own .vroom file.  Just make sure all
+of the lines are exactly $VROOM_WIDTH characters long and the file
+contains no more than $VROOM_HEIGHT_MAX lines. Make sure the file is
+readable by everyone (e.g. chmod ugo+r ~/.vroom) and that
+it is located at the top level of your home directory.
+
+Space Launch ignores any .vroom files that don't meet the
+file size requirements.  It's not rocket science; so don't
+get left on the launch pad!
+
+Command line options:
+ -t  : Reports if your .vroom file passes or fails spec.
+ -m  : Prints template .vroom file of size $VROOM_WIDTH x $VROOM_HEIGHT_MAX.
+       You can pipe this template into a .vroom file and
+       modify it.
+ -h  : Prints this help message. Duh!
+
+==========================================================
+EOM
+
+## CTRL-C TRAP - BLOW UP THE ROCKET WHEN ^c CAUGHT:
+ALTITUDE=1 ## INCREMENTS AS ROCKET GOES UP
+trap ctrl_c INT
+function ctrl_c() {
+  # PUSH ROCKET OFF THE SCREEN:
+  i=0
+  while [ $i -lt $TRAILING_SPACE ]; do
+    echo; i=$(($i+1))
+  done
+
+  cat $KABOOM
+
+    ## vv sed -e 's/^ *//' IS A BANDAID FOR SOME SYSTEM'S LEADING SPACE PADDING OF wc OUTPUT
+  KABOOM_HEIGHT=$(wc -l "$KABOOM" | sed -e 's/^ *//' | cut -d" " -f1);
+  if [ "$ALTITUDE" -ge $((TRAILING_SPACE-$KABOOM_HEIGHT)) ] && [ $KABOOM_HEIGHT -lt $TRAILING_SPACE ]; then
+    ALTITUDE=$(($TRAILING_SPACE-$KABOOM_HEIGHT))
+  elif [ "$ALTITUDE" -le "$KABOOM_HEIGHT" ]; then
+    ALTITUDE=0
+  fi
+
+  # PRINT EXTRA LINES TO PLACE KABOOM AT CORRECT HEIGHT
+  i=0
+  while [ $i -lt $ALTITUDE ]; do
+    echo
+    i=$(($i+1))
+  done 
+
+#  stty echo ## RE-ENABLE ECHO
+  exit
+}
+
+VALIDATE_VROOM () {
+  if [ -r $1 ]; then
+
+    while read -r line; do  ## lines in file
+      [ "${#line}" = "$VROOM_WIDTH" ] || PASS='fail'
+    done <$1
+
+    # CHECK THAT VROOM FILE IS UNDER HEIGHT LIMIT
+    VROOM_HEIGHT=$(wc -l $1 | cut -d" " -f1)
+    [ "$VROOM_HEIGHT" -gt "$VROOM_HEIGHT_MAX" ] && PASS='fail'
+
+  else
+    PASS='fail' # KICK IT OUT IF FILE IS UNREADABLE
+  fi
+}
+
+TEST_VROOM () {
+  echo
+  echo "=========================================================="
+  echo "Testing your .vroom file..."
+  echo
+
+  TEST_PASS_MSG="PASS! Your .vroom file meets requirements and will be included in future launches."
+
+  read -r -d '' TEST_FAIL_MSG << EOM
+FAIL! Your .vroom file does not meet one or more of the
+following requirements:
+
+ * Each line in the .vroom file must be exactly $VROOM_WIDTH
+   characters in length.
+
+ * The .vroom file may contain no more than $VROOM_HEIGHT_MAX lines.
+
+==========================================================
+EOM
+
+  PASS='pass'
+  VALIDATE_VROOM "$HOME_DIR/$USER/.vroom"
+  if [[ $PASS = 'pass' ]]; then
+    echo "PASS! Your .vroom file meets requirements and will be"
+    echo "included in future launches.";
+    echo "=========================================================="
+  elif [[ $PASS = 'fail' ]]; then echo "$TEST_FAIL_MSG";
+  else echo "This message indicates that a bug has occured. Please submit a copy of your .vroom accompanied by pitiless mockery to the developer."
+  fi
+  exit
+}
+
+CREATE_VROOM() {
+for i in $(seq 1 $VROOM_HEIGHT_MAX); do
+  for j in $(seq 1 $VROOM_WIDTH); do printf "="; done
+  echo
+done
+}
+
+#########################################################################
+## 3, 2, 1 LAUCH!  MAIN PROGRAM FLOW:
+
+[ "$1" = "-h" ] && echo "$HELP_TEXT" && exit
+[ "$1" = "-t" ] && TEST_VROOM && exit
+[ "$1" = "-m" ] && CREATE_VROOM && exit
+
+# CALCULATE ADDITIONAL PADDING NEEDED RELATIVE TO FLAMES:
+PADDING_SIZE=0
+IFS=''
+while read -r line; do
+  [ ${#line} -ge $PADDING_SIZE ] && PADDING_SIZE=${#line}
+done <$FLAMES
+PADDING_SIZE=$(($PADDING_SIZE-$VROOM_WIDTH))
+PADDING_SIZE=$(($PADDING_SIZE/2)) ## TO DO: WHAT IF PAD IS ODD?
+PADDING=$(printf '%*s' "$PADDING_SIZE" | tr ' ' " ")
+
+unset PASS
+
+# PRINT THE NOSE CONE
+while read -r line; do
+  echo "$PADDING$line"
+  sleep $SLEEP_TIME
+done <$NOSE_CONE
+
+# VALIDATE WIDTH AND HEIGHT OF ROCKET PARTS (FROM USERS)
+for i in ${ROCKET_PARTS[@]}; do
+  PASS='pass'
+
+  VALIDATE_VROOM $i
+
+  ## PRINT THE ROCKET PARTS (FROM USERS) IF CORRECT SIZE:
+  if [ "$PASS" = 'pass' ]; then
+    while read -r line; do  ## lines in file
+      echo "$PADDING$line";
+      sleep $SLEEP_TIME
+    done <$i
+  fi
+
+  unset PASS
+done
+
+# PRINT THE FLAMES:
+while read -r line; do  ## lines in file
+  echo "$line";
+  ALTITUDE=$((ALTITUDE+1))
+  sleep $SLEEP_TIME
+done <$FLAMES
+
+# PRINT EXTRA LINES TO KEEP ROCKET MOVING UP
+i=0
+while [ $i -lt $TRAILING_SPACE ]; do
+  echo
+  ALTITUDE=$((ALTITUDE+1))
+  sleep $SLEEP_TIME
+  i=$(($i+1))
+done
+
+## stty echo ## RE-ENABLE ECHO SO USERS CAN SEE WHAT THEY TYPE AGAIN
+exit