Cleaned up CMakeList.txt and improved README regeneration.

CMakeLists.txt

 project( "slop" )
 set( slop_VERSION_MAJOR 3 )
 set( slop_VERSION_MINOR 1 )
-set( slop_VERSION_PATCH 12 )
+set( slop_VERSION_PATCH 13 )
 
 set( BIN_TARGET     "${PROJECT_NAME}" )
 set( CMAKE_INSTALL_PREFIX "/usr/bin" )
 # so nobody has to go find and install gengetopt if they don't want to.
 find_program( GENGETOPT_EXECUTABLE gengetopt
               DOC "A tool to generate code to grab command line options." )
-find_program( SED_EXECUTABLE sed
-              DOC "A text replacement tool used to help generate code" )
-find_program( COPY_EXECUTABLE cp )
-if ( GENGETOPT_EXECUTABLE AND SED_EXECUTABLE AND COPY_EXECUTABLE )
-    message( "Executing " "${GENGETOPT_EXECUTABLE}" " " "--input=options.ggo" " " "--header-extension=in" )
-    execute_process( COMMAND
-                     "${GENGETOPT_EXECUTABLE}" "--input=options.ggo"
-                     WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src" )
-    execute_process( COMMAND
-                     "${COPY_EXECUTABLE}" "cmdline.h" "cmdline.in"
+find_program( SED_EXECUTABLE sed )
+if ( GENGETOPT_EXECUTABLE AND SED_EXECUTABLE )
+    message( "-- Regenerating cmdline.in" )
+    # gengetopt generates cmdline.h, then we move it to cmdline.in.
+    execute_process( COMMAND "${GENGETOPT_EXECUTABLE}" "--input=options.ggo"
                      WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src" )
+    file( RENAME "${CMAKE_CURRENT_SOURCE_DIR}/src/cmdline.h" "${CMAKE_CURRENT_SOURCE_DIR}/src/cmdline.in" )
     # Due to a bug in gengetopt, we have to manually insert some code.
     # Replace the first instance of REPLACEME with some text.
     # Eight backslashes = two in the code because of how many instances of escaping is happening.
-    message( "Replacing REPLACEME in generated code..." )
-    execute_process( COMMAND
-                     "${SED_EXECUTABLE}" "-i" "0,/REPLACEME/{s/REPLACEME/X=%x\\\\\\\\nY=%y\\\\\\\\nW=%w\\\\\\\\nH=%h\\\\\\\\nG=%g\\\\\\\\nID=%i\\\\\\\\nCancel=%c\\\\\\\\n/}" "cmdline.c"
+    execute_process( COMMAND "${SED_EXECUTABLE}" "-i" "0,/REPLACEME/{s/REPLACEME/X=%x\\\\\\\\nY=%y\\\\\\\\nW=%w\\\\\\\\nH=%h\\\\\\\\nG=%g\\\\\\\\nID=%i\\\\\\\\nCancel=%c\\\\\\\\n/}" "cmdline.c"
                      WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src" )
     # Then replace remaining instances.
-    execute_process( COMMAND
-                     "${SED_EXECUTABLE}" "-i" "s/REPLACEME/X=%x\\\\nY=%y\\\\nW=%w\\\\nH=%h\\\\nG=%g\\\\nID=%i\\\\nCancel=%c\\\\n/" "cmdline.c"
+    execute_process( COMMAND "${SED_EXECUTABLE}" "-i" "s/REPLACEME/X=%x\\\\nY=%y\\\\nW=%w\\\\nH=%h\\\\nG=%g\\\\nID=%i\\\\nCancel=%c\\\\n/" "cmdline.c"
                      WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src" )
 else()
-    message( "Command gengetopt or sed not found! Won't regenerate command line code." )
+    message( "Warning: Command gengetopt or sed not found! Won't regenerate command line code. (If you're just compiling this doesn't matter.)" )
 endif()
 
 # By default our src/options.ggo has our cmake versions variables for
 configure_file( "src/cmdline.in"
                 "src/cmdline.h" )
 
-# Here we need to make sure our README has the correct version inside of it.
-# We use a simple regex search and replace for it, but it seems really
-# hard because cmake is silly.
-# I think this is better than using configure_file since README.md needs
-# to exist within github, rather than as an input file with a different
-# name or extension.
-message( "Replacing version in readme..." )
-set( SEARCH_REGEX "slop v([0-9]+)\\.([0-9]+)\\.([0-9]+)" )
-set( REPLACE_TEXT "slop v${slop_VERSION_MAJOR}.${slop_VERSION_MINOR}.${slop_VERSION_PATCH}" )
-file( READ "${CMAKE_CURRENT_SOURCE_DIR}/README.md" FILE_CONTENT )
-string( REGEX REPLACE "${SEARCH_REGEX}" "${REPLACE_TEXT}"
-        MODIFIED_FILE_CONTENT "${FILE_CONTENT}" )
-file( WRITE "${CMAKE_CURRENT_SOURCE_DIR}/README.md" "${MODIFIED_FILE_CONTENT}" )
+# This allows for "make README.md" to be ran to update the README's help
+# section automatically. We don't add it to ALL because running arbitrary
+# scripts is unsafe and I don't know if systems will actually have it
+# be executbable.
+add_custom_target( README.md "./generateReadme.sh" DEPENDS "slop" )
 
 # Sources
 set( source
 set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmakemodules" )
 find_package( X11       REQUIRED )
 find_package( XExt      REQUIRED )
-find_package( RT        REQUIRED )
+# This library is needed only for Ubuntu it seems, some platforms don't even
+# ship with it. I couldn't find a way to do a test compile to check if librt
+# was needed, so instead I just didn't mark it as REQUIRED.
+find_package( RT )
 
 set( CMAKE_CXX_FLAGS
      "${CMAKE_CXX_FLAGS} ${CMAKE_IMLIB2_CXX_FLAGS}" )

README.md

 help
 ----
 ```text
-slop v3.1.12
+slop v3.1.13
 
 Copyright (C) 2014 Dalton Nell, Slop Contributors
 (https://github.com/naelstrof/slop/graphs/contributors)

generateReadme.sh

+#!/bin/bash
+# generateReadme.sh: Regenerates the help section of the README.md using output from ./slop --help.
+
+# Remove help section
+sed -i '/^help/,/^```$/d' README.md
+
+# Add the help section again.
+echo 'help' >> README.md
+echo '----' >> README.md
+echo '```text' >> README.md
+echo "$(./slop --help)" >> README.md
+echo '```' >> README.md