From cf7017c9c6de0dff046fb5820a660f5f6c482f7f Mon Sep 17 00:00:00 2001
From: CyberLeo <cyberleo@cyberleo.net>
Date: Sat, 6 Mar 2010 14:01:20 -0600
Subject: [PATCH] Add reexec scriptlet to exec things via sudo/su

---
 example.sh       | 10 +++++++++-
 lib/sh/reexec.sh | 30 ++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 lib/sh/reexec.sh

diff --git a/example.sh b/example.sh
index fc7ebcb..14ddcf6 100755
--- a/example.sh
+++ b/example.sh
@@ -3,7 +3,9 @@
 # Source shlib
 _root="$(dirname "${0}")"; . "${_root}/lib/sh/env.sh"
 
-want log ask
+want log ask reexec
+
+id
 
 note This is a note.
 log ...and a log...
@@ -12,5 +14,11 @@ warn ...warning...
 log "Are you sure?"
 yn || err you said no
 
+if [ "$(id -u)" -ne 0 ]
+then
+  note "Restart script as root"
+  reexec "${0}" "${@}"
+fi
+
 err the end
 
diff --git a/lib/sh/reexec.sh b/lib/sh/reexec.sh
new file mode 100644
index 0000000..d45f45a
--- /dev/null
+++ b/lib/sh/reexec.sh
@@ -0,0 +1,30 @@
+# reexec library script
+
+if [ -z "${__reexec_sh_loaded}" ]
+then
+  __reexec_sh_loaded=yes
+  
+  # exec a command via sudo/su
+  # Can be used to reexec this process, if run like this from the top-level:
+  #  reexec "${0}" "${@}"
+  # Specify target user name with -u as the first parameter
+  #  reexec -u user "${0}" "${@}"
+  reexec() {
+    user="root"
+    # Set name if user provided
+    if [ "${1}" = "-u" ]
+    then
+      user="${2}"
+      shift 2
+    fi
+    
+    # reexec if needed
+    if [ "$(id -un)" != "${user}" ]
+    then
+      # Find a su/sudo
+      cmd="sudo -u ${user}"
+      [ -x "$(which sudo 2>/dev/null)" ] || cmd="su ${user} -c"
+      exec ${cmd} "${@}"
+    fi
+  }
+fi
-- 
2.42.0