Removing debugging line

Closes #30

API.md

@@ -4,60 +4,94 @@ API / Function Documentation
 This documentation is generated automatically from the source of [mo] thanks to [tomdoc.sh].
 
 
-mo()
-----
+`mo()`
+------
 
 Public: Template parser function.  Writes templates to stdout.
 
 * $0 - Name of the mo file, used for getting the help message.
-* --fail-not-set - Fail upon expansion of an unset variable.  Default behavior is to silently ignore and expand into empty string.
-* --false        - Treat "false" as an empty value.  You may set the MO_FALSE_IS_EMPTY environment variable instead to a non-empty value to enable this behavior.
-* --help         - Display a help message.
-* --source=FILE  - Source a file into the environment before processint template files.
-* --             - Used to indicate the end of options.  You may optionally use this when filenames may start with two hyphens.
+* --allow-function-arguments - Permit functions in templates to be called with additional arguments. This puts template data directly in to the path of an eval statement. Use with caution. Not listed in the help because it only makes sense when mo is sourced.
+* --fail-not-set - (`-u`) Fail upon expansion of an unset variable.  Default behavior is to silently ignore and expand into empty string.
+* --false - (`-e`) Treat "false" as an empty value.  You may set the MO_FALSE_IS_EMPTY environment variable instead to a non-empty value to enable this behavior.
+* --help - (`-h)` Display a help message.
+* --source=FILE - (`-s=FILE`) Source a file into the environment before processing template files.
+* --path=PATH - (`-p=PATH`) Colon-separated list of paths to search for templates. They are relative to where `mo` was executed.
+* --  - Used to indicate the end of options.  You may use this when filenames start with hyphens.
 * $@ - Filenames to parse.
 
 Mo uses the following environment variables:
 
+* MO_ALLOW_FUNCTION_ARGUMENTS - When set to a non-empty value, this allows functions referenced in templates to receive additional options and arguments. This puts the content from the template directly into an eval statement. Use with extreme care.
+
 * MO_FAIL_ON_UNSET - When set to a non-empty value, expansion of an unset env variable will be aborted with an error.
+
 * MO_FALSE_IS_EMPTY - When set to a non-empty value, the string "false" will be treated as an empty value for the purposes of conditionals.
+
 * MO_ORIGINAL_COMMAND - Used to find the `mo` program in order to generate a help message.
 
-Returns nothing.
+* MO_SEARCH_PATH - Colon-separated list of folders to search for templates. They are relative to where `mo` was executed.
+
+Returns true (0) when there are no errors. Sometimes returns (1) when there are errors and sometimes those errors are consumed. It greatly depends on the error and your options.
 
 
-files
------
+`files`
+-------
 
 After we encounter two hyphens together, all the rest of the arguments are files.
 
 
-MO_FAIL_ON_UNSET
-----------------
+`MO_ALLOW_FUNCTION_ARGUMENTS`
+-----------------------------
 
 shellcheck disable=SC2030
 
 
-MO_FALSE_IS_EMPTY
------------------
+`MO_FAIL_ON_UNSET`
+------------------
 
 shellcheck disable=SC2030
 
 
-doubleHyphens
--------------
+`MO_FALSE_IS_EMPTY`
+-------------------
+
+shellcheck disable=SC2030
+
+
+`doubleHyphens`
+---------------
 
 Set a flag indicating we've encountered double hyphens
 
 
-files
------
+`files`
+-------
 
 Every arg that is not a flag or a option should be a file
 
 
-moFindEndTag()
---------------
+`moProcessSearchPath()`
+-----------------------
+
+Internal: Change relative paths into absolute paths
+
+
+`moCallFunction()`
+------------------
+
+Internal: Call a function.
+
+* $1 - Function to call
+* $2 - Content to pass
+* $3 - Additional arguments as a single string
+
+This can be dangerous, especially if you are using tags like {{someFunction ; rm -rf / }}
+
+Returns nothing.
+
+
+`moFindEndTag()`
+----------------
 
 Internal: Scan content until the right end tag is found.  Creates an array with the following members:
 
@@ -75,8 +109,8 @@ Everything using this function uses the "standalone tags" logic.
 Returns nothing.
 
 
-moFindString()
---------------
+`moFindString()`
+----------------
 
 Internal: Find the first index of a substring.  If not found, sets the index to -1.
 
@@ -87,8 +121,8 @@ Internal: Find the first index of a substring.  If not found, sets the index to
 Returns nothing.
 
 
-moFullTagName()
----------------
+`moFullTagName()`
+-----------------
 
 Internal: Generate a dotted name based on current context and target name.
 
@@ -99,8 +133,8 @@ Internal: Generate a dotted name based on current context and target name.
 Returns nothing.
 
 
-moGetContent()
---------------
+`moGetContent()`
+----------------
 
 Internal: Fetches the content to parse into a variable.  Can be a list of partials for files or the content from stdin.
 
@@ -110,8 +144,8 @@ Internal: Fetches the content to parse into a variable.  Can be a list of partia
 Returns nothing.
 
 
-moIndentLines()
----------------
+`moIndentLines()`
+-----------------
 
 Internal: Indent a string, placing the indent at the beginning of every line that has any content.
 
@@ -122,8 +156,8 @@ Internal: Indent a string, placing the indent at the beginning of every line tha
 Returns nothing.
 
 
-moIndirect()
-------------
+`moIndirect()`
+--------------
 
 Internal: Send a variable up to the parent of the caller of this function.
 
@@ -141,8 +175,8 @@ Examples
 Returns nothing.
 
 
-moIndirectArray()
------------------
+`moIndirectArray()`
+-------------------
 
 Internal: Send an array as a variable up to caller of a function
 
@@ -161,8 +195,8 @@ Examples
 Returns nothing.
 
 
-moIsArray()
------------
+`moIsArray()`
+-------------
 
 Internal: Determine if a given environment variable exists and if it is an array.
 
@@ -173,16 +207,16 @@ Be extremely careful.  Even if strict mode is enabled, it is not honored in newe
 Examples
 
     var=(abc)
-    if moIsArray var; the
+    if moIsArray var; then
        echo "This is an array"
-       echo "Make sure you don't accidentally use $var"
+       echo "Make sure you don't accidentally use \$var"
     fi
 
 Returns 0 if the name is not empty, 1 otherwise.
 
 
-moIsFunction()
---------------
+`moIsFunction()`
+----------------
 
 Internal: Determine if the given name is a defined function.
 
@@ -202,8 +236,8 @@ Examples
 Returns 0 if the name is a function, 1 otherwise.
 
 
-moIsStandalone()
-----------------
+`moIsStandalone()`
+------------------
 
 Internal: Determine if the tag is a standalone tag based on whitespace before and after the tag.
 
@@ -223,8 +257,8 @@ Examples
 Returns nothing.
 
 
-moJoin()
---------
+`moJoin()`
+----------
 
 Internal: Join / implode an array
 
@@ -235,8 +269,8 @@ Internal: Join / implode an array
 Returns nothing.
 
 
-moLoadFile()
-------------
+`moLoadFile()`
+--------------
 
 Internal: Read a file into a variable.
 
@@ -246,8 +280,8 @@ Internal: Read a file into a variable.
 Returns nothing.
 
 
-moLoop()
---------
+`moLoop()`
+----------
 
 Internal: Process a chunk of content some number of times.  Writes output to stdout.
 
@@ -258,8 +292,8 @@ Internal: Process a chunk of content some number of times.  Writes output to std
 Returns nothing.
 
 
-moParse()
----------
+`moParse()`
+-----------
 
 Internal: Parse a block of text, writing the result to stdout.
 
@@ -270,8 +304,14 @@ Internal: Parse a block of text, writing the result to stdout.
 Returns nothing.
 
 
-moPartial()
------------
+`moArgs`
+--------
+
+Split arguments from the tag name. Arguments are passed to functions.
+
+
+`moPartial()`
+-------------
 
 Internal: Process a partial.
 
@@ -291,8 +331,14 @@ Prefix all variables.
 Returns nothing.
 
 
-moShow()
---------
+`IFS`
+-----
+
+Search the path for the file
+
+
+`moShow()`
+----------
 
 Internal: Show an environment variable or the output of a function to stdout.
 
@@ -300,12 +346,13 @@ Limit/prefix any variables used.
 
 * $1 - Name of environment variable or function
 * $2 - Current context
+* $3 - Arguments string if $1 is a function
 
 Returns nothing.
 
 
-moSplit()
----------
+`moSplit()`
+-----------
 
 Internal: Split a larger string into an array.
 
@@ -317,8 +364,8 @@ Internal: Split a larger string into an array.
 Returns nothing.
 
 
-moStandaloneAllowed()
----------------------
+`moStandaloneAllowed()`
+-----------------------
 
 Internal: Handle the content for a standalone tag.  This means removing whitespace (not newlines) before a tag and whitespace and a newline after a tag.  That is, assuming, that the line is otherwise empty.
 
@@ -331,8 +378,8 @@ Internal: Handle the content for a standalone tag.  This means removing whitespa
 Returns nothing.
 
 
-moStandaloneDenied()
---------------------
+`moStandaloneDenied()`
+----------------------
 
 Internal: Handle the content for a tag that is never "standalone".  No adjustments are made for newlines and whitespace.
 
@@ -344,8 +391,8 @@ Internal: Handle the content for a tag that is never "standalone".  No adjustmen
 Returns nothing.
 
 
-moTest()
---------
+`moTest()`
+----------
 
 Internal: Determines if the named thing is a function or if it is a non-empty environment variable.  When MO_FALSE_IS_EMPTY is set to a non-empty value, then "false" is also treated is an empty value.
 
@@ -358,8 +405,8 @@ Do not use variables without prefixes here if possible as this needs to check if
 Returns 0 if the name is not empty, 1 otherwise.  When MO_FALSE_IS_EMPTY is set, this returns 1 if the name is "false".
 
 
-moTestVarSet()
---------------
+`moTestVarSet()`
+----------------
 
 Internal: Determine if a variable is assigned, even if it is assigned an empty value.
 
@@ -368,8 +415,8 @@ Internal: Determine if a variable is assigned, even if it is assigned an empty v
 Returns true (0) if the variable is set, 1 if the variable is unset.
 
 
-moTrimChars()
--------------
+`moTrimChars()`
+---------------
 
 Internal: Trim the leading whitespace only.
 
@@ -382,8 +429,8 @@ Internal: Trim the leading whitespace only.
 Returns nothing.
 
 
-moTrimWhitespace()
-------------------
+`moTrimWhitespace()`
+--------------------
 
 Internal: Trim leading and trailing whitespace from a string.
 
@@ -393,8 +440,8 @@ Internal: Trim leading and trailing whitespace from a string.
 Returns nothing.
 
 
-moUsage()
----------
+`moUsage()`
+-----------
 
 Internal: Displays the usage for mo.  Pulls this from the file that contained the `mo` function.  Can only work when the right filename comes is the one argument, and that only happens when `mo` is called with `$0` set to this file.
 
@@ -403,8 +450,8 @@ Internal: Displays the usage for mo.  Pulls this from the file that contained th
 Returns nothing.
 
 
-MO_ORIGINAL_COMMAND
--------------------
+`MO_ORIGINAL_COMMAND`
+---------------------
 
 Save the original command's path for usage later
 

README.md

@@ -27,7 +27,7 @@ Requirements
 * The "coreutils" package (`basename` and `cat`)
 * ... that's it.  Why?  Because bash **can**!
 
-If you intend to develop this and run the official specs, you also need node.js.
+If you intend to develop this and run the official specs, you also need Node.js.
 
 
 Installation
@@ -41,7 +41,7 @@ There are a few ways you can install this tool.  How you install it depends on h
 You can install this file in `/usr/local/bin/` or `/usr/bin/` by simply downloading it, changing the permissions, then moving it to the right location.  Double check that your system's PATH includes the destination folder, otherwise users may have a hard time starting the command.
 
     # Download
-    curl -sSO https://raw.githubusercontent.com/tests-always-included/mo/master/mo
+    curl -sSL https://git.io/get-mo -o mo
 
     # Make executable
     chmod +x mo
@@ -58,7 +58,7 @@ You can install this file in `/usr/local/bin/` or `/usr/bin/` by simply download
 This is very similar to installing it globally but it does not require root privileges.  It is very important that your PATH includes the destination folder otherwise it won't work.  Some local folders that are typically used are `~/bin/` and `~/.local/bin/`.
 
     # Download
-    curl -sSO https://raw.githubusercontent.com/tests-always-included/mo/master/mo
+    curl -sSL https://git.io/get-mo -o mo
 
     # Make executable
     chmod +x mo
@@ -78,7 +78,7 @@ This is very similar to installing it globally but it does not require root priv
 Bash scripts can source `mo` to include the functionality in their own routines.  This usage typically would have `mo` saved to a `lib/` folder in an application and your other scripts would use `. lib/mo` to bring it into your project.
 
     # Download
-    curl -sSO https://raw.githubusercontent.com/tests-always-included/mo/master/mo
+    curl -sSL https://git.io/get-mo -o mo
 
     # Move into your project folder
     mv mo ~/projects/amazing-things/lib/
@@ -115,6 +115,8 @@ The result?  You get a list of the five elements in the array.  It is vital that
 
 There are more scripts available in the [demos directory](demo/) that could help illustrate how you would use this program.
 
+There are additional features that the program supports. Try using `mo --help` to see what is available.
+
 
 Concessions
 -----------

demo/function-for-advanced-looping

@@ -3,6 +3,9 @@
 cd "$(dirname "$0")" # Go to the script's directory
 
 EVERY_REPO() {
+    # The block contents come in through standard input. Capture it here.
+    content=$(cat)
+
     echo "# Starting EVERY_REPO"
 
     # Get list of repos
@@ -14,7 +17,7 @@ EVERY_REPO() {
         # It rewrites {{__REPO__.name}} into {{resque.name}}, for instance.
         # You can prefix your environment variables and do other things as well.
         
-        echo -n "$1" | sed "s/__REPO__/${REPO}/"
+        echo "$content" | sed "s/__REPO__/${REPO}/"
 
         echo "## Looped one time for repo: $REPO"
     done

demo/function-for-building-json

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+cd "$(dirname "$0")" # Go to the script's directory
+
+# Detect if this is the first item and write a comma if it is.
+# Normally, I would track this using a variable, like so:
+#
+# COMMA_IF_NOT_FIRST_FLAG=false
+# COMMA_IF_NOT_FIRST() {
+#     $COMMA_IF_NOT_FIRST || echo ","
+#     COMMA_IF_NOT_FIRST_FLAG=true
+# }
+#
+# Since this function executes in a subshell, that approach will not work.
+# Instead, we peek inside mo and see what is being processed. If the variable
+# name in moParse() changes, this will need to get updated as well. An
+# alternate variable that is usable is context, but that is in moLoop() and is
+# two levels levels deep instead of just one.
+COMMA_IF_NOT_FIRST() {
+    [[ "${moCurrent#*.}" != "0" ]] && echo ","
+}
+
+# Create an array that will be embedded into the JSON. If you are manipulating
+# JSON, might I suggest you look at using jq? It's really good at processing
+# JSON.
+items=(
+    '{"position":"one","url":"1"}'
+    '{"position":"two","url":"2"}'
+    '{"position":"three","url":"3"}'
+)
+. ../mo
+cat <<EOF | mo
+{
+    {{#items}}
+    {{COMMA_IF_NOT_FIRST}}
+    {{.}}
+    {{/items}}
+}
+EOF

demo/function-for-foreach

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# Example for how #29 can get implemented.
+
+cd "$(dirname "$0")" # Go to the script's directory
+
+foreach() {
+    # Trying to use unique names
+    local foreachSourceName foreachIterator foreachEvalString foreachContent
+
+    foreachContent=$(cat)
+
+    if [[ "$2" != "as" && "$2" != "in" ]]; then
+        echo "Invalid foreach - bad format."
+    elif [[ "$(declare -p "$1")" != "declare -"[aA]* ]]; then
+        echo "$1 is not an array"
+    else
+        foreachSourceName="${1}[@]"
+
+        for foreachIterator in "${!foreachSourceName}"; do
+            foreachEvalString=$(declare -p "$foreachIterator")
+            foreachEvalString="declare -A $3=${foreachEvalString#*=}"
+            eval "$foreachEvalString"
+            echo "$foreachContent" | mo
+        done
+    fi
+}
+
+
+# The links are associative arrays
+declare -A resque hub rip
+resque=([name]=Resque [url]=http://example.com/resque)
+hub=([name]=Hub [url]=http://example.com/hub)
+rip=([name]=Rip [url]=http://example.com/rip)
+
+# This is a list of the link arrays
+links=(resque hub rip)
+
+# Source mo in order to work with arrays
+. ../mo
+
+# Process the template
+cat <<EOF | mo --allow-function-arguments
+Here are your links:
+{{#foreach links as link}}
+ * [{{link.name}}]({{link.url}})
+{{/foreach}}
+
+EOF

demo/important-file

@@ -2,13 +2,17 @@
 
 cd "$(dirname "$0")"/..
 
-date-string() { date; }
-wrapper() { echo -n "*** $1 ***"; }
+date-string() {
+    date
+}
+wrapper() {
+    echo -n "*** $(cat) ***"
+}
 
 export IP=127.0.0.1
 export ALLOWED_HOSTS=( 192.168.0.1 192.168.0.2 192.168.0.3 )
 
-. mo  # Keep in mind this script is executing in the parent directory
+. ./mo  # Keep in mind this script is executing in the parent directory
 cat <<EOF | mo
 # {{#wrapper}}OH SO IMPORTANT{{/wrapper}}
 # This file automatically generated at {{date-string}}

demo/relative-templates/child1

@@ -0,0 +1,3 @@
+* Child1
+{{> deeper/child2 }}
+{{> ../relative-templates/deeper/child2 }}

demo/relative-templates/child3

@@ -0,0 +1 @@
+        * Child3

demo/relative-templates/deeper/child2

@@ -0,0 +1,2 @@
+    * Child2
+{{> ../child3 }}

demo/relative-templates/file

@@ -0,0 +1,7 @@
+This is "file"
+
+Child1 in different ways
+{{> child1 }}
+{{> ./child1 }}
+{{> ../relative-templates/child1 }}
+{{> deeper/../child1 }}

mo

@@ -11,12 +11,20 @@
 #/
 #/ Simple usage:
 #/
-#/    mo [--false] [--help] [--source=FILE] filenames...
+#/    mo [OPTIONS] filenames...
 #/
-#/ --fail-not-set - Fail upon expansion of an unset variable.
-#/ --false        - Treat the string "false" as empty for conditionals.
-#/ --help         - This message.
-#/ --source=FILE  - Load FILE into the environment before processing templates.
+#/ Options:
+#/
+#/    -u, --fail-not-set
+#/          - Fail upon expansion of an unset variable.
+#/    -e, --false
+#/          - Treat the string "false" as empty for conditionals.
+#/    -h, --help
+#/          - This message.
+#/    -s=FILE, --source=FILE
+#/          - Load FILE into the environment before processing templates.
+#/    -p=PATH, --path=PATH
+#/          - Set a colon-delimited list of folders to search for templates.
 #
 # Mo is under a MIT style licence with an additional non-advertising clause.
 # See LICENSE.md for the full text.
@@ -29,33 +37,50 @@
 # Public: Template parser function.  Writes templates to stdout.
 #
 # $0 - Name of the mo file, used for getting the help message.
-# --fail-not-set - Fail upon expansion of an unset variable.  Default behavior
-#                  is to silently ignore and expand into empty string.
-# --false        - Treat "false" as an empty value.  You may set the
-#                  MO_FALSE_IS_EMPTY environment variable instead to a non-empty
-#                  value to enable this behavior.
-# --help         - Display a help message.
-# --source=FILE  - Source a file into the environment before processint
+# --allow-function-arguments - Permit functions in templates to be called with
+#         additional arguments. This puts template data directly in to the path
+#         of an eval statement. Use with caution. Not listed in the help
+#         because it only makes sense when mo is sourced.
+# --fail-not-set - (`-u`) Fail upon expansion of an unset variable.  Default
+#         behavior is to silently ignore and expand into empty string.
+# --false - (`-e`) Treat "false" as an empty value.  You may set the
+#         MO_FALSE_IS_EMPTY environment variable instead to a non-empty value
+#         to enable this behavior.
+# --help - (`-h)` Display a help message.
+# --source=FILE - (`-s=FILE`) Source a file into the environment before processing
 #         template files.
-# --             - Used to indicate the end of options.  You may optionally
-#                  use this when filenames may start with two hyphens.
+# --path=PATH - (`-p=PATH`) Colon-separated list of paths to search for templates.
+#         They are relative to where `mo` was executed.
+# --  - Used to indicate the end of options.  You may use this when filenames
+#         start with hyphens.
 # $@ - Filenames to parse.
 #
 # Mo uses the following environment variables:
 #
-# MO_FAIL_ON_UNSET    - When set to a non-empty value, expansion of an unset
-#                       env variable will be aborted with an error.
-# MO_FALSE_IS_EMPTY   - When set to a non-empty value, the string "false"
-#                       will be treated as an empty value for the purposes
-#                       of conditionals.
-# MO_ORIGINAL_COMMAND - Used to find the `mo` program in order to generate
-#                       a help message.
+# MO_ALLOW_FUNCTION_ARGUMENTS - When set to a non-empty value, this allows
+#         functions referenced in templates to receive additional options and
+#         arguments. This puts the content from the template directly into an
+#         eval statement. Use with extreme care.
 #
-# Returns nothing.
+# MO_FAIL_ON_UNSET - When set to a non-empty value, expansion of an unset env
+#         variable will be aborted with an error.
+#
+# MO_FALSE_IS_EMPTY - When set to a non-empty value, the string "false" will be
+#         treated as an empty value for the purposes of conditionals.
+#
+# MO_ORIGINAL_COMMAND - Used to find the `mo` program in order to generate a
+#         help message.
+#
+# MO_SEARCH_PATH - Colon-separated list of folders to search for templates.
+#         They are relative to where `mo` was executed.
+#
+# Returns true (0) when there are no errors. Sometimes returns (1) when there
+# are errors and sometimes those errors are consumed. It greatly depends on the
+# error and your options.
 mo() (
     # This function executes in a subshell so IFS is reset.
     # Namespace this variable so we don't conflict with desired values.
-    local moContent f2source files doubleHyphens
+    local moContent f2source files doubleHyphens paths
 
     IFS=$' \n\t'
     files=()
@@ -74,18 +99,23 @@ mo() (
                         exit 0
                         ;;
 
-                    --fail-not-set)
+                    --allow-function-arguments)
+                        # shellcheck disable=SC2030
+                        MO_ALLOW_FUNCTION_ARGUMENTS=true
+                        ;;
+
+                    -u | --fail-not-set)
                         # shellcheck disable=SC2030
                         MO_FAIL_ON_UNSET=true
                         ;;
 
-                    --false)
+                    -e | --false)
                         # shellcheck disable=SC2030
                         MO_FALSE_IS_EMPTY=true
                         ;;
 
-                    --source=*)
-                        f2source="${arg#--source=}"
+                    -s=* | --source=*)
+                        f2source="${arg#*=}"
 
                         if [[ -f "$f2source" ]]; then
                             # shellcheck disable=SC1090
@@ -96,6 +126,10 @@ mo() (
                         fi
                         ;;
 
+                    -p=* | --path=*)
+                        MO_SEARCH_PATH="$(moProcessSearchPath "${arg#*=}")"
+                        ;;
+
                     --)
                         # Set a flag indicating we've encountered double hyphens
                         doubleHyphens=true
@@ -115,6 +149,45 @@ mo() (
 )
 
 
+# Internal: Change relative paths into absolute paths
+moProcessSearchPath() {
+    local in out path startingPwd IFS
+
+    IFS=:
+    startingPwd=$PWD
+    
+    for path in $1; do
+        cd "$startingPwd" && cd "$path" 2>/dev/null && out="$out:$PWD"
+    done
+
+    echo "${out:1}"
+}
+
+
+# Internal: Call a function.
+#
+# $1 - Function to call
+# $2 - Content to pass
+# $3 - Additional arguments as a single string
+#
+# This can be dangerous, especially if you are using tags like
+# {{someFunction ; rm -rf / }}
+#
+# Returns nothing.
+moCallFunction() {
+    local moArgs
+
+    moArgs=()
+
+    # shellcheck disable=SC2031
+    if [[ -n "${MO_ALLOW_FUNCTION_ARGUMENTS-}" ]]; then
+        moArgs=$3
+    fi
+
+    echo -n "$2" | eval "$1" "$moArgs"
+}
+
+
 # Internal: Scan content until the right end tag is found.  Creates an array
 # with the following members:
 #
@@ -567,7 +640,7 @@ moLoop() {
 moParse() {
     # Keep naming variables mo* here to not overwrite needed variables
     # used in the string replacements
-    local moBlock moContent moCurrent moIsBeginning moNextIsBeginning moTag
+    local moArgs moBlock moContent moCurrent moIsBeginning moNextIsBeginning moTag
 
     moCurrent=$2
     moIsBeginning=$3
@@ -585,6 +658,13 @@ moParse() {
                 # Sets context
                 moStandaloneAllowed moContent "${moContent[@]}" "$moIsBeginning"
                 moTrimWhitespace moTag "${moTag:1}"
+                
+                # Split arguments from the tag name. Arguments are passed to
+                # functions.
+                moArgs=$moTag
+                moTag=${moTag%% *}
+                moTag=${moTag%%$'\t'*}
+                moArgs=${moArgs:${#moTag}}
                 moFindEndTag moBlock "$moContent" "$moTag"
                 moFullTagName moTag "$moCurrent" "$moTag"
 
@@ -593,7 +673,7 @@ moParse() {
                     if moIsFunction "$moTag"; then
                         #: Consider piping the output to moGetContent
                         #: so the lambda does not execute in a subshell?
-                        moContent=$($moTag "${moBlock[0]}")
+                        moContent=$(moCallFunction "$moTag" "${moBlock[0]}" "$moArgs")
                         moParse "$moContent" "$moCurrent" false
                         moContent="${moBlock[2]}"
                     elif moIsArray "$moTag"; then
@@ -658,11 +738,16 @@ moParse() {
                 moContent="${moTag:1}"'}}'"$moContent"
                 moSplit moContent "$moContent" '}}}'
                 moTrimWhitespace moTag "${moContent[0]}"
+                moArgs=$moTag
+                moTag=${moTag%% *}
+                moTag=${moTag%%$'\t'*}
+                moArgs=${moArgs:${#moTag}}
                 moFullTagName moTag "$moCurrent" "$moTag"
                 moContent=${moContent[1]}
 
                 # Now show the value
-                moShow "$moTag" "$moCurrent"
+                # Quote moArgs here, do not quote it later.
+                moShow "$moTag" "$moCurrent" "$moArgs"
                 ;;
 
             '&'*)
@@ -676,8 +761,14 @@ moParse() {
             *)
                 # Normal environment variable or function call
                 moStandaloneDenied moContent "${moContent[@]}"
+                moArgs=$moTag
+                moTag=${moTag%% *}
+                moTag=${moTag%%$'\t'*}
+                moArgs=${moArgs:${#moTag}}
                 moFullTagName moTag "$moCurrent" "$moTag"
-                moShow "$moTag" "$moCurrent"
+
+                # Quote moArgs here, do not quote it later.
+                moShow "$moTag" "$moCurrent" "$moArgs"
                 ;;
         esac
 
@@ -733,7 +824,39 @@ moPartial() {
     (
         # It would be nice to remove `dirname` and use a function instead,
         # but that's difficult when you're only given filenames.
-        cd "$(dirname -- "$moFilename")" || exit 1
+        if ! cd "$(dirname -- "$moFilename")"; then
+            if [[ -n "${MO_FAIL_ON_UNSET-}" ]]; then
+                echo "Error changing to directory: $(dirname -- "$moFilename")" >&2
+                exit 1
+            fi
+
+            # Mustache likes to be silent when there are errors.
+            exit 0
+        fi
+
+        if [[ "$moFilename" != */* ]] && [[ ! -f "$moFilename" ]] && [[ -n "$MO_SEARCH_PATH" ]]; then
+            # Search the path for the file
+            IFS=:
+            
+            for moSearchPath in $MO_SEARCH_PATH; do
+                if [[ ! -f "$moFilename" ]]; then
+                    cd "$moSearchPath"
+                fi
+            done
+
+            IFS=$' \n\t'
+        fi
+
+        if [[ ! -f "${moFilename##*/}" ]]; then
+            if [[ -n "${MO_FAIL_ON_UNSET-}" ]]; then
+                echo "File does not exist: $PWD/${moFilename##*/}" >&2
+                exit 1
+            fi
+
+            # Mustache likes to be silent when there are errors.
+            exit 0
+        fi
+
         moUnindented="$(
             moLoadFile moPartial "${moFilename##*/}" || exit 1
             moParse "${moPartial}" "$6" true
@@ -763,6 +886,7 @@ moPartial() {
 #
 # $1 - Name of environment variable or function
 # $2 - Current context
+# $3 - Arguments string if $1 is a function
 #
 # Returns nothing.
 moShow() {
@@ -770,22 +894,22 @@ moShow() {
     local moJoined moNameParts
 
     if moIsFunction "$1"; then
-        CONTENT=$($1 "")
+        CONTENT=$(moCallFunction "$1" "" "$3")
         moParse "$CONTENT" "$2" false
         return 0
     fi
 
     moSplit moNameParts "$1" "."
 
-    if [[ -z "${moNameParts[1]}" ]]; then
+    if [[ -z "${moNameParts[1]-}" ]]; then
         if moIsArray "$1"; then
             eval moJoin moJoined "," "\${$1[@]}"
             echo -n "$moJoined"
         else
             # shellcheck disable=SC2031
-            if [[ -z "$MO_FAIL_ON_UNSET" ]] || moTestVarSet "$1"; then
+            if moTestVarSet "$1"; then
                 echo -n "${!1}"
-            else
+            elif [[ -n "${MO_FAIL_ON_UNSET-}" ]]; then
                 echo "Env variable not set: $1" >&2
                 exit 1
             fi
@@ -972,11 +1096,14 @@ moTrimWhitespace() {
 # Returns nothing.
 moUsage() {
     grep '^#/' "${MO_ORIGINAL_COMMAND}" | cut -c 4-
+    echo ""
+    set | grep ^MO_VERSION=
 }
 
 
 # Save the original command's path for usage later
 MO_ORIGINAL_COMMAND="$(cd "${BASH_SOURCE[0]%/*}" || exit 1; pwd)/${BASH_SOURCE[0]##*/}"
+MO_VERSION="2.0.4"
 
 # If sourced, load all functions.
 # If executed, perform the actions as expected.

tests/double-hyphen.expected

@@ -1 +1 @@
-cat: --help: No such file or directory
+File does not exist: /home/fidian/repo/mo/tests/--help

tests/double-hyphen.sh

@@ -2,4 +2,4 @@
 # This should display a message indicating that the file --help
 # could not be found.  It should not display a help messsage.
 cd "${0%/*}"
-../mo -- --help 2>&1
+../mo -u -- --help 2>&1

tests/function-args.env

@@ -0,0 +1,13 @@
+name=Willy
+MO_ALLOW_FUNCTION_ARGUMENTS=true
+
+pipeTo() {
+    cat | "$1"
+}
+
+testArgs() {
+    printf "%d" "$#"
+
+    # Display all arguments
+    printf " %q" ${@+"$@"}
+}

tests/function-args.expected

@@ -0,0 +1,4 @@
+No args: 0 '' - done
+One arg: 1 one - done
+Getting name in a string: 1 The\ name\ is\ Willy - done
+Reverse this: edcba

tests/function-args.template

@@ -0,0 +1,4 @@
+No args: {{testArgs}} - done
+One arg: {{testArgs one}} - done
+Getting name in a string: {{testArgs "The name is $name"}} - done
+Reverse this: {{#pipeTo rev}}abcde{{/pipeTo}}

tests/function.env

@@ -1,5 +1,5 @@
 name=Willy
 wrapped() {
-    # The final newline is eaten by mo
-    echo "<b>$1</b>"
+    # This eats the newline in the content
+    echo "<b>$(cat)</b>"
 }

tests/function.expected

@@ -1,2 +1 @@
-<b>  Willy is awesome.
-</b>... this is the last line.
+<b>  Willy is awesome.</b>... this is the last line.

tests/help.expected

@@ -9,9 +9,19 @@ Learn more about mustache templates at https://mustache.github.io/
 
 Simple usage:
 
-   mo [--false] [--help] [--source=FILE] filenames...
+   mo [OPTIONS] filenames...
 
---fail-not-set - Fail upon expansion of an unset variable.
---false        - Treat the string "false" as empty for conditionals.
---help         - This message.
---source=FILE  - Load FILE into the environment before processing templates.
+Options:
+
+   -u, --fail-not-set
+         - Fail upon expansion of an unset variable.
+   -e, --false
+         - Treat the string "false" as empty for conditionals.
+   -h, --help
+         - This message.
+   -s=FILE, --source=FILE
+         - Load FILE into the environment before processing templates.
+   -p=PATH, --path=PATH
+         - Set a colon-delimited list of folders to search for templates.
+
+MO_VERSION=2.0.4

tests/help.sh

@@ -1,4 +1,4 @@
 #!/usr/bin/env bash
 
 cd "${0%/*}"
-../mo --help
+../mo -u --help

tests/invalid-option.expected

@@ -1 +0,0 @@
-cat: --something: No such file or directory

tests/partial-missing.expected

@@ -1 +1 @@
-cat: partial-missing.partial: No such file or directory
+File does not exist: /home/fidian/repo/mo/tests/partial-missing.partial

tests/partial-missing.sh

@@ -1,8 +1,9 @@
 #!/usr/bin/env bash
 
 cd "${0%/*}"
-../mo partial-missing.template 2>&1
+../mo -u partial-missing.template 2>&1
+returned=$?
 
-if [[ $? -ne 1 ]]; then
-    echo "Did not return 1"
+if [[ $returned -ne 1 ]]; then
+    echo "Did not return 1. Instead, returned $returned."
 fi

tests/source.sh

@@ -1,7 +1,8 @@
 #!/usr/bin/env bash
 
 cd "${0%/*}"
-cat <<EOF | ../mo --source=source.vars
+. ../mo
+cat <<EOF | mo --source=source.vars
 {{VAR}}
 {{#ARR}}
 * {{.}}

tests/source.vars

@@ -1,4 +1,4 @@
 export VAR=value
 export ARR=(1 2 3)
 declare -A ASSOC_ARR
-export ASSOC_ARR=([a]=AAA [b]=BBB)
+ASSOC_ARR=([a]=AAA [b]=BBB)