diff --git a/bashrc b/bashrc
index ddc4699..d19a7c1 100644
--- a/bashrc
+++ b/bashrc
@@ -71,7 +71,7 @@ if [ -z "$BASHRCSOURCED" ]; then
     # Current threshold for system reserved uid/gids is 200
     # You could check uidgid reservation validity in
     # /usr/share/doc/setup-*/uidgid file
-    if [ $UID -gt 199 ] && [ "`id -gn`" = "`id -un`" ]; then
+    if [ $UID -gt 199 ] && [ "`/usr/bin/id -gn`" = "`/usr/bin/id -un`" ]; then
        umask 002
     else
        umask 022
diff --git a/csh.cshrc b/csh.cshrc
index d6fae9d..b83d5da 100644
--- a/csh.cshrc
+++ b/csh.cshrc
@@ -7,7 +7,7 @@
 # Current threshold for system reserved uid/gids is 200
 # You could check uidgid reservation validity in
 # /usr/share/doc/setup-*/uidgid file
-if ($uid > 199 && "`id -gn`" == "`id -un`") then
+if ($uid > 199 && "`/usr/bin/id -gn`" == "`/usr/bin/id -un`") then
     umask 002
 else
     umask 022
@@ -20,7 +20,7 @@ if ($?prompt) then
     # make completion work better by default
     set autolist
   else
-    set prompt=\[$user@`hostname -s`\]\$\ 
+    set prompt=\[$user@`/usr/bin/hostname -s`\]\$\ 
   endif
 endif
 
diff --git a/lang.csh b/lang.csh
index 695c1bc..94c4625 100644
--- a/lang.csh
+++ b/lang.csh
@@ -8,7 +8,7 @@ endif
 foreach config (/etc/locale.conf "${HOME}/.i18n")
     if (-f "${config}") then
         # NOTE: We are using eval & sed here to avoid invoking of any commands & functions from those files.
-        eval `sed -r -e 's/^[[:blank:]]*([[:upper:]_]+)=([[:print:][:digit:]\._-]+|"[[:print:][:digit:]\._-]+")/setenv \1 \2;/;t;d' ${config}`
+        eval `/usr/bin/sed -r -e 's/^[[:blank:]]*([[:upper:]_]+)=([[:print:][:digit:]\._-]+|"[[:print:][:digit:]\._-]+")/setenv \1 \2;/;t;d' ${config}`
     endif
 end
 
@@ -32,11 +32,11 @@ if (${?LC_ALL}) then
 endif
 
 # The ${LANG} manipulation is necessary only in virtual terminal (a.k.a. console - /dev/tty*):
-set in_console=`tty | grep -vc -e '/dev/tty'`
+set in_console=`/usr/bin/tty | /usr/bin/grep -vc -e '/dev/tty'`
 
 if (${?LANG} && ${?TERM}) then
     if (${TERM} == 'linux' && $in_console == 0) then
-        set utf8_used=`echo ${LANG} | grep -vc -E -i -e '^.+\.utf-?8$'`
+        set utf8_used=`echo ${LANG} | /usr/bin/grep -vc -E -i -e '^.+\.utf-?8$'`
 
         if (${utf8_used} == 0) then
             switch (${LANG})
diff --git a/lang.sh b/lang.sh
index 0252b0f..c9022d0 100644
--- a/lang.sh
+++ b/lang.sh
@@ -8,7 +8,7 @@ fi
 for config in /etc/locale.conf "${HOME}/.i18n"; do
     # NOTE: We are using eval & sed here to avoid invoking of any commands & functions from those files.
     if [ -f "${config}" ]; then
-        eval $(sed -r -e 's/^[[:blank:]]*([[:upper:]_]+)=([[:print:][:digit:]\._-]+|"[[:print:][:digit:]\._-]+")/export \1=\2/;t;d' ${config})
+        eval $(/usr/bin/sed -r -e 's/^[[:blank:]]*([[:upper:]_]+)=([[:print:][:digit:]\._-]+|"[[:print:][:digit:]\._-]+")/export \1=\2/;t;d' ${config})
     fi
 done
 
@@ -32,8 +32,8 @@ if [ -n "${LC_ALL}" ]; then
 fi
 
 # The ${LANG} manipulation is necessary only in virtual terminal (a.k.a. console - /dev/tty*):
-if [ -n "${LANG}" ] && [ "${TERM}" = 'linux' ] && tty | grep --quiet -e '/dev/tty'; then
-    if grep --quiet -E -i -e '^.+\.utf-?8$' <<< "${LANG}"; then
+if [ -n "${LANG}" ] && [ "${TERM}" = 'linux' ] && /usr/bin/tty | /usr/bin/grep --quiet -e '/dev/tty'; then
+    if /usr/bin/grep --quiet -E -i -e '^.+\.utf-?8$' <<< "${LANG}"; then
         case ${LANG} in
             ja*)    LANG=en_US.UTF-8 ;;
             ko*)    LANG=en_US.UTF-8 ;;
diff --git a/profile b/profile
index 1feb987..16b2e69 100644
--- a/profile
+++ b/profile
@@ -25,10 +25,10 @@ pathmunge () {
 if [ -x /usr/bin/id ]; then
     if [ -z "$EUID" ]; then
         # ksh workaround
-        EUID=`id -u`
-        UID=`id -ru`
+        EUID=`/usr/bin/id -u`
+        UID=`/usr/bin/id -ru`
     fi
-    USER="`id -un`"
+    USER="`/usr/bin/id -un`"
     LOGNAME=$USER
     MAIL="/var/spool/mail/$USER"
 fi
@@ -56,7 +56,7 @@ export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL
 # Current threshold for system reserved uid/gids is 200
 # You could check uidgid reservation validity in
 # /usr/share/doc/setup-*/uidgid file
-if [ $UID -gt 199 ] && [ "`id -gn`" = "`id -un`" ]; then
+if [ $UID -gt 199 ] && [ "`/usr/bin/id -gn`" = "`/usr/bin/id -un`" ]; then
     umask 002
 else
     umask 022