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author | Tom Ryder <tom@sanctum.geek.nz> | 2017-04-05 20:06:39 +1200 |
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committer | Tom Ryder <tom@sanctum.geek.nz> | 2017-04-05 20:46:47 +1200 |
commit | c8ab406749124d2e762ad5cf53963070113afd0f (patch) | |
tree | 54c9721a06957ebe7098a211eea803b0230c0f5d /games/dr.sh | |
parent | Handle POSIX correctness in ~/.bash_profile (diff) | |
download | dotfiles-c8ab406749124d2e762ad5cf53963070113afd0f.tar.gz dotfiles-c8ab406749124d2e762ad5cf53963070113afd0f.zip |
Apply runtime shebanging to POSIX shell
Diffstat (limited to 'games/dr.sh')
-rw-r--r-- | games/dr.sh | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/games/dr.sh b/games/dr.sh new file mode 100644 index 00000000..e1db163d --- /dev/null +++ b/games/dr.sh @@ -0,0 +1,36 @@ +#!/bin/sh +# Roll D&D-style dice in a ndn+n formula, e.g. 10d6+2 + +# Need exactly one argument +[ "$#" -eq 1 ] || exit 2 + +# Arcane string chopping +n=1 a=0 +nd=${1%+*} +d=${nd#*d} +[ "${nd%d*}" != "" ] && n=${nd%d*} +[ "${1#*+}" = "$1" ] || a=${1#*+} + +# Check number of roles and addendum make sense +[ "$((n > 0 && a >= 0))" -eq 1 ] || exit 2 + +# Check this is a real die you can actually roll +case $d in + 4|6|8|10|12|20) : ;; + *) exit 2 ;; +esac + +# Roll the dice the appropriate number of times using rndi(1df) +i=0 t=0 +while [ "$i" -lt "$n" ] ; do + seed=$(rnds) + r=$(rndi 1 "$d" "$seed") + t=$((t + r)) + i=$((i + 1)) +done + +# Add the addendum +t=$((t + a)) + +# Print it +printf '%u\n' "$t" |