From 53486847d1b8dffd483408cf1e97b796ae1cb2a8 Mon Sep 17 00:00:00 2001
From: Pierre Hyvernat <pierre.hyvernat@univ-smb.fr>
Date: Mon, 7 Jun 2021 12:20:45 +0200
Subject: [PATCH] external script for saving environment

---
 bin/save_environment.sh | 13 +++++++++++++
 lib/gsh.sh              | 25 +++++++++++++++----------
 lib/mission_source.sh   | 39 +++++++++------------------------------
 3 files changed, 37 insertions(+), 40 deletions(-)
 create mode 100644 bin/save_environment.sh

diff --git a/bin/save_environment.sh b/bin/save_environment.sh
new file mode 100644
index 00000000..48c08773
--- /dev/null
+++ b/bin/save_environment.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# this script should be **sourced**
+# it will output the current environment: names of variables, functions,
+# aliases and processes
+
+{
+  compgen -v          | sed 's/^/Variable:/'
+  compgen -A function | sed 's/^/Function:/'
+  compgen -a          | sed 's/^/Alias:/'
+  ps -o pid,comm      | sed '1d;s/^/Process:/'
+} | grep -vE "grep|ps|sed|sort|bash" | sort
+
diff --git a/lib/gsh.sh b/lib/gsh.sh
index dd389e94..5c923d11 100644
--- a/lib/gsh.sh
+++ b/lib/gsh.sh
@@ -207,15 +207,19 @@ _gsh_start() {
 
   # re-source static.sh, in case some important directory was removed by accident
   [ -f "$MISSION_DIR/static.sh" ] && mission_source "$MISSION_DIR/static.sh"
+
   if [ -f "$MISSION_DIR/init.sh" ]
   then
-    # attention, si l'initialisation a lieu dans un sous-shell et qu'elle
-    # définit des variables d'environnement, elles ne seront pas définies dans
-    # la session bash.
-    # je sauvegarde l'environnement avant / après l'initialisation pour
-    # afficher un message dans ce cas
+    # If init.sh is sourced in a subshell, variable definitions, changes of
+    # PWD, functions or aliases defined in init.sh will disappear.
+    # I save the environment before / after and display a warning when that's the case.
     _PWD=$(pwd)
-    [ "$BASHPID" = $$ ] || compgen -v | sort > "$GSH_VAR"/env-before
+    if [ "$BASHPID" != $$ ]
+    then
+      local env_before=$(mktemp)
+      . save_environment.sh > "$env_before"
+    fi
+
     mission_source "$MISSION_DIR/init.sh"
     local exit_status=$?
 
@@ -227,17 +231,18 @@ _gsh_start() {
       return
     fi
 
-    [ "$BASHPID" = $$ ] || compgen -v | sort > "$GSH_VAR"/env-after
-
     if [ "$BASHPID" != $$ ]
     then
-      if [ "$_PWD" != "$(pwd)" ] || ! cmp -s "$GSH_VAR"/env-before "$GSH_VAR"/env-after
+      local env_after=$(mktemp)
+      . save_environment.sh > "$env_after"
+
+      if [ "$_PWD" != "$(pwd)" ] || ! cmp -s "$env_before" "$env_after"
       then
         echo "$(gettext "Error: this mission was initialized in a subshell.
 You should run the command
     \$ gsh reset
 to make sure the mission is initialized properly.")" >&2
-        rm -f "$GSH_VAR"/env-{before,after}
+        rm -f "$/env_before" "$env_after"
       fi
     fi
   fi
diff --git a/lib/mission_source.sh b/lib/mission_source.sh
index 434dab28..abf4ecb9 100644
--- a/lib/mission_source.sh
+++ b/lib/mission_source.sh
@@ -52,7 +52,6 @@ mission_source() {
   fi
 
   echo "    GSH: sourcing \$GSH_ROOT/${FILENAME#$GSH_ROOT/}" >&2
-  local TEMP=$(mktemp -d "$GSH_VAR/env-XXXXXX")
   local source_ret_value=""  # otherwise, it appears in the environment!
   local _MISSION_DIR=""
   local _TEXTDOMAIN=""
@@ -60,12 +59,12 @@ mission_source() {
   local MISSION_NAME=""
   local _PATH=""
   local exit_status=""
+  local env_before=$(mktemp)
+  local env_after=$(mktemp)
 
   # otherwise, record the environment (variables, functions and aliases)
   # before and after to echo a message when there are differences
-  compgen -v | sort > "$TEMP"/before-V
-  compgen -A function | sort > "$TEMP"/before-F
-  compgen -a | sort > "$TEMP"/before-A
+  . save_environment.sh >"$env_before"
   local _MISSION_DIR=$MISSION_DIR
   export MISSION_DIR=$(dirname "$(realpath "$FILENAME")")
   _TEXTDOMAIN=$TEXTDOMAIN
@@ -80,36 +79,16 @@ mission_source() {
   export MISSION_NAME=$_MISSION_NAME
   export MISSION_DIR=$_MISSION_DIR
   export PATH=$_PATH
-  compgen -v | sort > "$TEMP"/after-V
-  compgen -A function | sed "/$MISSION_FN/d" | sort > "$TEMP"/after-F
-  compgen -a | sort > "$TEMP"/after-A
+  . save_environment.sh | grep -v "$MISSION_FN" > "$env_after"
 
-  local msg="GSH: environment modifications while sourcing \$GSH_ROOT/${FILENAME#$GSH_ROOT/}" >&2
-  if ! cmp -s "$TEMP"/{before,after}-V
+  if ! cmp -s "$env_before" "$env_after"
   then
-    [ -n "$msg" ] && echo "$msg"
-    msg=""
-    comm -23 "$TEMP"/{before,after}-V | sed "s/^/-Var:/"
-    comm -13 "$TEMP"/{before,after}-V | sed "s/^/+Var:/"
+    echo "GSH: environment modifications while sourcing \$GSH_ROOT/${FILENAME#$GSH_ROOT/}" >&2
+    comm -23 "$env_before" "$env_after" | sed "s/^/-/"
+    comm -13 "$env_before" "$env_after" | sed "s/^/+/"
   fi
 
-  if ! cmp -s "$TEMP"/{before,after}-F
-  then
-    [ -n "$msg" ] && echo "$msg"
-    msg=""
-    comm -23 "$TEMP"/{before,after}-F | sed "s/^/-Fun:/"
-    comm -13 "$TEMP"/{before,after}-F | sed "s/^/+Fun:/"
-  fi
-
-  if ! cmp -s "$TEMP"/{before,after}-A
-  then
-    [ -n "$msg" ] && echo "$msg"
-    msg=""
-    comm -23 "$TEMP"/{before,after}-A | sed "s/^/-Aliase:/"
-    comm -13 "$TEMP"/{before,after}-A | sed "s/^/+Aliase:/"
-  fi
-
-  rm -rf "$TEMP"
+  rm -f "$env_before" "$env_after"
   unset -f "$MISSION_FN"
   return $exit_status
 }