base-files: Add /etc/shinit for non-login shell init

Because /etc/profile (and ~/.profile) are read by login shells only,
aliases and functions defined there are not available to non-login
shells, e.g. when using screen or tmux.

If the ENV environment variable exists (exported by /etc/profile or
~/.profile) and references an existing file, then all interactive shells
(login or non-login) will read that file as well.

This sets the ENV environment variable in /etc/profile, pointing to
/etc/shinit.

This also adds /etc/shinit, which:

* Contains alias and function definitions originally in /etc/profile

* Sources /etc/mkshrc if the user is using mksh (also originally in
  /etc/profile), as /etc/mkshrc is meant for all interactive shells

* Sources ~/.mkshrc if the user is using mksh, to compensate for the
  fact that mksh will not read ~/.mkshrc if ENV is set

* Sources ~/.shinit if the user is not using mksh

This also removes the shebang from /etc/profile, as the file is sourced,
not executed.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

package/base-files/Makefile

@@ -72,6 +72,7 @@ define Package/base-files/conffiles
 /etc/services
 /etc/shadow
 /etc/shells
+/etc/shinit
 /etc/sysctl.conf
 /etc/sysupgrade.conf
 $(call $(TARGET)/conffiles)

package/base-files/files/etc/profile

@@ -1,4 +1,3 @@
-#!/bin/sh
 [ -e /tmp/.failsafe ] && export FAILSAFE=1
 
 [ -f /etc/banner ] && cat /etc/banner
@@ -13,6 +12,7 @@ export PATH="%PATH%"
 export HOME=$(grep -e "^${USER:-root}:" /etc/passwd | cut -d ":" -f 6)
 export HOME=${HOME:-/root}
 export PS1='\u@\h:\w\$ '
+export ENV=/etc/shinit
 
 case "$TERM" in
 	xterm*|rxvt*)
@@ -20,16 +20,6 @@ case "$TERM" in
 		;;
 esac
 
-[ -x /bin/more ] || alias more=less
-[ -x /usr/bin/vim ] && alias vi=vim || alias vim=vi
-
-alias ll='ls -alF --color=auto'
-
-[ -z "$KSH_VERSION" -o \! -s /etc/mkshrc ] || . /etc/mkshrc
-
-[ -x /usr/bin/arp -o -x /sbin/arp ] || arp() { cat /proc/net/arp; }
-[ -x /usr/bin/ldd ] || ldd() { LD_TRACE_LOADED_OBJECTS=1 $*; }
-
 [ -n "$FAILSAFE" ] || {
 	for FILE in /etc/profile.d/*.sh; do
 		[ -e "$FILE" ] && . "$FILE"
@@ -48,12 +38,3 @@ in order to prevent unauthorized SSH logins.
 --------------------------------------------------
 EOF
 fi
-
-service() {
-	[ -f "/etc/init.d/$1" ] || {
-		echo "service "'"'"$1"'"'" not found, the following services are available:"
-		ls "/etc/init.d"
-		return 1
-	}
-	/etc/init.d/$@
-}

package/base-files/files/etc/shinit

@@ -0,0 +1,21 @@
+[ -x /bin/more ] || alias more=less
+[ -x /usr/bin/vim ] && alias vi=vim || alias vim=vi
+
+alias ll='ls -alF --color=auto'
+
+[ -z "$KSH_VERSION" -o \! -s /etc/mkshrc ] || . /etc/mkshrc
+
+[ -x /usr/bin/arp -o -x /sbin/arp ] || arp() { cat /proc/net/arp; }
+[ -x /usr/bin/ldd ] || ldd() { LD_TRACE_LOADED_OBJECTS=1 $*; }
+
+service() {
+	[ -f "/etc/init.d/$1" ] || {
+		echo "service "'"'"$1"'"'" not found, the following services are available:"
+		ls "/etc/init.d"
+		return 1
+	}
+	/etc/init.d/$@
+}
+
+[ -n "$KSH_VERSION" -o \! -s "$HOME/.shinit" ] || . "$HOME/.shinit"
+[ -z "$KSH_VERSION" -o \! -s "$HOME/.mkshrc" ] || . "$HOME/.mkshrc"

package/base-files/files/lib/upgrade/keep.d/base-files-essential

@@ -6,5 +6,6 @@
 /etc/profile
 /etc/shadow
 /etc/shells
+/etc/shinit
 /etc/sysctl.conf
 /etc/rc.local