From 60b97759b78b2b8bd0b8d20804c1a0c76642fe75 Mon Sep 17 00:00:00 2001
From: CyberLeo <cyberleo@cyberleo.net>
Date: Thu, 28 Apr 2011 12:12:17 -0500
Subject: [PATCH] j: function and variable namespace cleanup

---
 exec  |  1 +
 j     | 86 +++++++++++++++++++++++++++++++++++++----------------------
 shell |  1 +
 3 files changed, 56 insertions(+), 32 deletions(-)
 create mode 120000 exec
 create mode 120000 shell

diff --git a/exec b/exec
new file mode 120000
index 0000000..0fe2fa5
--- /dev/null
+++ b/exec
@@ -0,0 +1 @@
+j
\ No newline at end of file
diff --git a/j b/j
index a1ca67c..581973c 100755
--- a/j
+++ b/j
@@ -2,43 +2,68 @@
 # Copyright 2011 CyberLeo, All Rights Reserved
 # http://wiki.cyberleo.net/wiki/CyberLeo/COPYRIGHT
 
-meh() { printf " \033[1;32m*\033[0m %s%s\n" "${jail:+${jail}: }" "${*}"; }
-omg() { printf " \033[1;33m*\033[0m %s%s\n" "${jail:+${jail}: }" "${*}"; }
-wtf() { printf " \033[1;31m*\033[0m %s%s\n" "${jail:+${jail}: }" "${*}"; exit 1; }
+# Need root beyond here
+[ "$(id -u)" -eq 0 ] || exec sudo "${0}" "${@}"
+
+meh() { printf " \033[1;32m*\033[0m %s%s\n" "${jname:+${jname}: }" "${*}"; }
+omg() { printf " \033[1;33m*\033[0m %s%s\n" "${jname:+${jname}: }" "${*}"; }
+wtf() { printf " \033[1;31m*\033[0m %s%s\n" "${jname:+${jname}: }" "${*}"; exit 1; }
 pebkac() {
   [ "${*}" ] && printf "%s\n\n" "${*}"
   cat <<EOF
-Usage: <start|enter|stop> <jailname>
+Usage: <list|ls|start|enter|exec|shell|stop> <jailname>
+Usage:
+  <command> <jail> [arguments]
+  list
+  ls      list available jails
+
+  status  show jail status
+
+  start   prepare an existing jail for use
+
+  stop    undo what 'start' did
+
+  exec
+  enter
+  shell   spawn a shell or command within the jail
+
 EOF
   exit 1
 }
 
 cmd="$(basename "${0}")"
-base="${J_BASE:-$(realpath "$(dirname "${0}")/../")}"
-jail="${J_NAME:-$(basename "${1:-DebianChroot}")}" #"
-jdir="${base}/${jail}"
-jail_shell=""
+jbase="${J_BASE:-$(realpath "$(dirname "${0}")/../")}"
+jname="${J_NAME:-$(basename "${1}")}" #"
+
+# Remove jail name from argument stack, if passed in
+[ "${J_NAME}" ] || shift
 
 # Propagate certain environment variables; sterilize the rest of the environment
-jail_env="
+jenv="
+  LANG=${LANG}
   TERM=${TERM}
   USER=${USER}
 "
 
-# Create a new jail, somehow
-jail_init() {
+# Create a new chroot, somehow
+j_init() {
   # Either a debian jail with debootstrap or a gentoo jail with stage3 + portage tarballs
   DEBOOTSTRAP_DIR="$(base)/debootstrap" "${DEBOOTSTRAP_DIR}/debootstrap" --arch=amd64 squeeze "${jdir}"
 }
 
-# Figure out jail parameters
-jail_params() {
+# Figure out and set jail parameters; needed for all functions that follow
+j_params() {
+  jname="${1:-jname}"
+  # Given a jail name, find and set up the jail dir
+  jdir="${jbase}/${jname}"
+  [ -d "${jdir}" ] || wtf "not a directory"
+
   # Where is the shell?
   for shell in /bin/bash /usr/bin/bash /usr/local/bin/bash /bin/sh
   do
     if [ -f "${jdir}/${shell}" ]
     then
-      jail_shell=${shell}
+      jshell=${shell}
       break
     fi
     wtf "cannot locate usable shell; is this a real jail?"
@@ -46,48 +71,45 @@ jail_params() {
 }
 
 # Jail is 'up' if /dev/pts and /proc are mounted
-jail_up() {
+j_up() {
   grep -q "^devpts ${jdir}/dev/pts devpts" /proc/mounts || return 1
   grep -q "^proc ${jdir}/proc proc" /proc/mounts || return 1
   return 0
 }
 
-jail_status() {
-  jail_up && meh "$(printf '\033[1;32mup\033[0m')" || meh "$(printf '\033[1;31mdown\033[0m')"
+j_status() {
+  j_up && meh "$(printf '\033[1;32mup\033[0m')" || meh "$(printf '\033[1;31mdown\033[0m')"
 }
 
 # Mount /dev/pts and /proc in the jail
-jail_start() {
-  jail_up && return 0
+j_start() {
+  j_up && return 0
   meh "starting ${jail} ..."
   mount -t devpts devpts "${jdir}/dev/pts"
   mount -t proc proc "${jdir}/proc"
 }
 
 # Enter jail
-jail_enter() {
-  jail_up || wtf "jail not up"
+j_exec() {
+  j_up || wtf "jail not up"
   meh "entering ${jail} ..."
-  env -i ${jail_env} /usr/bin/chroot "${jdir}" /bin/su "${USER}" -c "${jail_shell}" -l
+  exec env -i ${jenv} /usr/bin/chroot "${jdir}" /bin/su "${juser:-${USER}}" -c "${jshell}" -l
 }
 
 # Unmount /dev/pts and /proc in the jail
-jail_stop() {
-  jail_up || return 0
+j_stop() {
+  j_up || return 0
   meh "stopping ${jail} ..."
   umount "${jdir}/proc"
   umount "${jdir}/dev/pts"
 }
 
-# Need root beyond here
-[ "$(id -u)" -eq 0 ] || exec sudo env ${jail_env} "${0}" "${@}"
-
-jail_params
+j_params "${jname}"
 
 case "${cmd}" in
-status) jail_status ;;
-start) jail_start ;;
-enter) jail_enter ;;
-stop)  jail_stop  ;;
+status) j_status ;;
+start) j_start ;;
+enter|exec|shell) j_exec "${@}" ;;
+stop)  j_stop  ;;
 *) pebkac ;;
 esac
diff --git a/shell b/shell
new file mode 120000
index 0000000..0fe2fa5
--- /dev/null
+++ b/shell
@@ -0,0 +1 @@
+j
\ No newline at end of file
-- 
2.42.0