From a18f52b6a1a83c04555696f78e61d64d05ee990c Mon Sep 17 00:00:00 2001
From: Ben Ashton <ben@n0m.org>
Date: Wed, 28 Sep 2022 23:05:02 -0600
Subject: [PATCH] Initial commit

---
 README.md        |  50 +++++++++++++++++++++
 examples/cats.sh |  33 ++++++++++++++
 src/exprash.sh   | 114 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 197 insertions(+)
 create mode 100644 README.md
 create mode 100644 examples/cats.sh
 create mode 100644 src/exprash.sh

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c15617b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,50 @@
+# Exprash
+
+An Express-like HTTP router for Bash compatible with CGI 1.1
+
+I'm aware that the name of this project evokes a feeling of physical disgust. That is by design.
+
+## Usage/Examples
+
+Here is some leaked source code for my brand new Cat website. Do not steal!
+
+```shell
+#!/bin/bash
+printf '%s\n\n' 'Content-Type: text/html';
+
+source ../src/exprash.sh;
+
+declare -A cats;
+cats[calico]="Calico";
+cats[sphynx]="Sphynx";
+cats[ragdoll]="Ragdoll";
+cats[scottish_fold]="Scottish Fold";
+
+get '/' && {
+  printf '<h1>Cats</h1>\n';
+  printf '<ul>\n';
+  for key in "${!cats[@]}"; do
+    printf '<li><a href="cats/%s">%s</a></li>\n' "$key" "${cats[$key]}";
+  done
+  printf '</ul>\n';
+}
+
+get '/cats/:cat' && {
+  key=$(param 'cat');
+
+  if [[ -v "cats[$key]" ]]; then
+    printf '<h1>Your Cat: %s</h1>\n' "${cats[$key]}";
+  else
+    next;
+  fi;
+}
+
+all '/cats/:cat' && {
+  printf '<h1>Error: Cannot find that cat</h1>\n';
+}
+```
+
+
+## License
+
+[WTFPL](http://www.wtfpl.net/txt/copying/)
diff --git a/examples/cats.sh b/examples/cats.sh
new file mode 100644
index 0000000..eadc019
--- /dev/null
+++ b/examples/cats.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+printf '%s\n\n' 'Content-Type: text/html';
+
+source ../src/exprash.sh;
+
+declare -A cats;
+cats[calico]="Calico";
+cats[sphynx]="Sphynx";
+cats[ragdoll]="Ragdoll";
+cats[scottish_fold]="Scottish Fold";
+
+get '/' && {
+  printf '<h1>Cats</h1>\n';
+  printf '<ul>\n';
+  for key in "${!cats[@]}"; do
+    printf '<li><a href="cats/%s">%s</a></li>\n' "$key" "${cats[$key]}";
+  done
+  printf '</ul>\n';
+}
+
+get '/cats/:cat' && {
+  key=$(param 'cat');
+
+  if [[ -v "cats[$key]" ]]; then
+    printf '<h1>Your Cat: %s</h1>\n' "${cats[$key]}";
+  else
+    next;
+  fi;
+}
+
+all '/cats/:cat' && {
+  printf '<h1>Error: Cannot find that cat</h1>\n';
+}
\ No newline at end of file
diff --git a/src/exprash.sh b/src/exprash.sh
new file mode 100644
index 0000000..5ba4214
--- /dev/null
+++ b/src/exprash.sh
@@ -0,0 +1,114 @@
+#!/bin/bash
+# shellcheck disable=SC2034 # false flags nameref params
+
+# =============
+# Route Methods
+# =============
+
+# $1: path
+function get() {
+  [ "$REQUEST_METHOD" != "GET" ] && return 1;
+  all "$1";
+}
+
+# $1: path
+function post() {
+  [ "$REQUEST_METHOD" != "POST" ] && return 1;
+  all "$1";
+}
+
+# $1: path
+function put() {
+  [ "$REQUEST_METHOD" != "PUT" ] && return 1;
+  all "$1";
+}
+
+# $1: path
+function delete() {
+  [ "$REQUEST_METHOD" != "DELETE" ] && return 1;
+  all "$1";
+}
+
+# $1: path
+function all() {
+  [ "$routeHandled" -eq 1 ] && return 1;
+
+  # Reset params
+  params=();
+  pathMatch "$1" params || return 1;
+
+  # # if path ooesn't match PATH_INFO: return 1
+  routeHandled=1;
+  return 0;
+}
+
+function next() {
+  routeHandled=0;
+}
+
+# =================
+# Request Functions
+# =================
+
+# $1: param name
+function param() {
+  printf '%s\n' "${params[$1]}";
+}
+
+# $1: param name
+function hasParam() {
+  [[ -v "params[$1]" ]];
+}
+
+# =========
+# Internals
+# =========
+
+# $1: path
+# $2: (nameref) array
+function pathToArray() {
+  readarray -t "$2" < <(printf '%s\n' "$1" | tr '/' '\n' | grep .);
+}
+
+# $1: route
+# $2: (nameref) associative array for params
+function pathMatch() {
+  [ -z ${PATH_INFO+x} ] && return 1;
+  [ -z ${1+x} ] && return 1;
+
+  local path="$PATH_INFO";
+  local route="$1";
+
+  local pathArr;
+  pathToArray "$path" pathArr;
+
+  local routeArr;
+  pathToArray "$route" routeArr;
+
+  # Params associative array
+  local -n routeParams="$2";
+
+  # Not a match if pathArr and routeArr have different length
+  [ "${#pathArr[@]}" -ne "${#routeArr[@]}" ] && return 1;
+
+  for ((i=0; i<${#routeArr[@]}; i++)); do
+    local routeComponent="${routeArr[$i]}";
+    local pathComponent="${pathArr[$i]}";
+
+    # If route component starts with ":"
+    if [[ "$routeComponent" == :* ]]; then
+      routeParams["${routeComponent:1}"]="$pathComponent";
+    else
+      # Confirm paths match
+      [ "$routeComponent" != "$pathComponent" ] && return 1;
+    fi;
+  done;
+
+  return 0;
+}
+
+# =======
+# Globals
+# =======
+routeHandled=0;
+declare -A params;