From 2f8c462c0f16230e9aa7e099cfc5dc36d80912e0 Mon Sep 17 00:00:00 2001
From: Tiiffi <tiiffi@gmail.com>
Date: Fri, 16 Dec 2016 21:13:01 +0200
Subject: [PATCH] Added support for setting basic options with environment
 variables.

---
 README.md |  6 ++++++
 mcrcon.1  | 12 +++++++++++-
 mcrcon.c  | 20 ++++++++++++++------
 3 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index f59367a..508b952 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,12 @@ Option:
   -v            Output version information
 ```
 
+Server address, port and password can be set using following environment variables:
+  MCRCON_HOST
+  MCRCON_PORT
+  MCRCON_PASS
+
+Command-line options will override environment variables.
 Commands with arguments must be enclosed in quotes.
 
 Example:
diff --git a/mcrcon.1 b/mcrcon.1
index 0a51872..b11f5d2 100644
--- a/mcrcon.1
+++ b/mcrcon.1
@@ -1,7 +1,7 @@
 .\" Process this file with
 .\" groff -man -Tascii mcrcon.1
 .\"
-.TH MCRCON 1 "November 2016" "Version 0.0.6"
+.TH MCRCON 1 "December 2016" "Version 0.0.6"
 .SH NAME 
 mcrcon \- sends rcon commands to a Minecraft server
 .SH SYNOPSIS
@@ -34,6 +34,16 @@ Output raw packets (for debugging and custom handling)
 Output version information
 .PP
 Commands with arguments must be enclosed in quotes.
+.SH ENVIRONMENTAL VARIABLES
+Server address, port and password can be set using following environment variables:
+.PP
+\fBMCRCON_HOST
+.br
+\fBMCRCON_PORT
+.br
+\fBMCRCOM_PASS\fR
+.PP
+Note that command-line options will override environment variables.
 .SH EXAMPLES
 Make rcon connection in terminal mode using default port
 .RS
diff --git a/mcrcon.c b/mcrcon.c
index 7263e3e..77c626a 100644
--- a/mcrcon.c
+++ b/mcrcon.c
@@ -140,11 +140,14 @@ int main(int argc, char *argv[])
 	int opt, ret = 0;
 	int terminal_mode = 0;
 
-	char *host = NULL;
-	char *pass = NULL;
-	char *port = "25575";
+	char *host = getenv("MCRCON_HOST");
+	char *pass = getenv("MCRCON_PASS");
+	char *port = getenv("MCRCON_PORT");
+	
+	if (!port)
+		port = "25575";
 
-	if(argc < 2)
+	if(argc < 2 && host == NULL && pass == NULL)
 		usage();
 
 	// default getopt error handler enabled
@@ -247,11 +250,16 @@ void usage(void)
 		"  -s\t\tSilent mode (do not print received packets)\n"
 		"  -c\t\tDisable colors\n"
 		"  -r\t\tOutput raw packets (debugging and custom handling)\n"
-		"  -v\t\tOutput version information\n"
+		"  -v\t\tOutput version information\n\n"
+		"Server address, port and password can be set using following environment variables:\n"
+		"  MCRCON_HOST\n"
+		"  MCRCON_PORT\n"
+		"  MCRCON_PASS\n\n"
 		,stdout
 	);
 
-	puts("\nCommands with arguments must be enclosed in quotes.\n");
+	puts("Command-line options will override environment variables.");
+	puts("Rcon commands with arguments must be enclosed in quotes.\n");
 	puts("Example:\n\t"IN_NAME" -H my.minecraft.server -p password \"say Server is restarting!\" save-all stop\n");
 	puts(VER_STR"\nReport bugs to tiiffi_at_gmail_dot_com or https://github.com/Tiiffi/mcrcon/issues/\n");