Implemented read EDITOR env variable

Now we detect which editor the user wants to use based on their
environment variable EDITOR. If none is set, use vim by default. Tested
with vim, vi, nano, cat (not an editor), and leafpad.

2 files changed, 9 insertions, 2 deletions

diff --git a/TODO.adoc b/TODO.adoc
index aaf3b38..fa8dec8 100644
--- a/TODO.adoc
+++ b/TODO.adoc
@@ -7,7 +7,7 @@ Implement
 * [x] File decryption to temp path
 * [x] File re-encryption
 * [ ] Comment all functions
-* [ ] Read environment variable $EDITOR, default to vim (only parse arg 0 to
+* [X] Read environment variable $EDITOR, default to vim (only parse arg 0 to
       some avoid security concerns)
 * [ ] Argument parser (eg: -r,--recipient)
 * [x] Recipient addition beyond the list already in the file
diff --git a/src/main.c b/src/main.c
index ca0df5c..2ddae06 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,7 +26,14 @@
 
 void system_edit(char* file) {
   char cmd[256]; // Buffer for editor command
-  sprintf(cmd, "%s %s\n", "vim", file);
+  char* editor;  // Editor to use when editing the file
+
+  // Read the environment variable for "EDITOR". If null, default to vim.
+  editor = getenv("EDITOR");
+  if(editor == NULL)
+    editor = "vim";
+
+  sprintf(cmd, "%s %s\n", editor, file);
   system(cmd);
 }