* Fix build issues - fix build order

* Plugin directory renamed to 'p'
* Add env.sh to enter into a "radare2 development shell"

--HG--
rename : libr/io/plugins/Makefile => libr/io/p/Makefile
rename : libr/io/plugins/README => libr/io/p/README
rename : libr/io/plugins/dbg.c => libr/io/p/dbg.c
rename : libr/io/plugins/malloc.c => libr/io/p/malloc.c
rename : libr/io/plugins/ptrace.c => libr/io/p/ptrace.c

Makefile

@@ -3,3 +3,10 @@ all:
 
 clean:
 	cd libr && make clean
+
+install:
+	mkdir -p prefix
+	cd libr && make install PREFIX=${PWD}/prefix
+
+deinstall:
+	rm -rf prefix

env.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+
+new_env='
+LIBR_PLUGINS=$PATH:$PWD/prefix/lib/radare2
+PATH=$PATH:$PWD/prefix/bin
+LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PWD/prefix/lib
+'
+
+echo
+echo "==> Entering radare2 environment shell..."
+echo
+echo $new_env $SHELL \
+   | sed -e 's, ,\n,g' \
+   | sed -e 's,^,  ,g' \
+   | sed -e 's,$,\\,'
+echo
+
+eval $new_env $SHELL
+
+echo
+echo "==> Back to system shell..."
+echo

libr/Makefile

@@ -2,7 +2,7 @@
 PREFIX=/tmp/libr-install
 
 # Libraries
-LIBLIST=io io/plugins util bin macro hash print config flags cons line lib syscall range socket cmd asm search core diff debug reg
+LIBLIST=io io/p util lib lang bin macro hash line cons print config flags syscall range socket cmd asm search diff debug reg core
 
 
 # Under development

libr/core/cmd.c

@@ -652,7 +652,7 @@ static int r_core_cmd_subst(struct r_core_t *core, char *cmd, int *rs, int *rfd,
 		*times = len;
 	}
 	if (cmd[0]=='\0')
-		return;
+		return 0;
 
 	/* quoted / raw command */
 	if (cmd[0]=='"') {