Minimal web server using netcat

Solution 1:

Try this:

while true ; do nc -l -p 1500 -c 'echo -e "HTTP/1.1 200 OK\n\n $(date)"'; done

The -cmakes netcat execute the given command in a shell, so you can use echo. If you don't need echo, use -e. For further information on this, try man nc. Note, that when using echo there is no way for your program (the date-replacement) to get the browser request. So you probably finally want to do something like this:

while true ; do nc -l -p 1500 -e /path/to/yourprogram ; done

Where yourprogram must do the protocol stuff like handling GET, sending HTTP 200 etc.

Solution 2:

I had the problem where I wanted to return the result of executing a bash command:

$ while true; do { echo -e 'HTTP/1.1 200 OK\r\n'; sh test; } | nc -l 8080; done

NOTE:
This command was taken from: http://www.razvantudorica.com/08/web-server-in-one-line-of-bash

This executes a bash script and returns the result to a browser client connecting to the server running this command on port 8080.

My script does this:

$ nano test

#!/bin/bash

echo "************PRINT SOME TEXT***************\n"
echo "Hello World!!!"
echo "\n"

echo "Resources:"
vmstat -S M
echo "\n"

echo "Addresses:"
echo "$(ifconfig)"
echo "\n"


echo "$(gpio readall)"

and my web browser is showing

************PRINT SOME TEXT***************

Hello World!!!


Resources:
procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 0  0      0    314     18     78    0    0     2     1  306   31  0  0 100  0


Addresses:
eth0      Link encap:Ethernet  HWaddr b8:27:eb:86:e8:c5  
          inet addr:192.168.1.83  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:27734 errors:0 dropped:0 overruns:0 frame:0
          TX packets:26393 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1924720 (1.8 MiB)  TX bytes:3841998 (3.6 MiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)


GPIOs:
+----------+-Rev2-+------+--------+------+-------+
| wiringPi | GPIO | Phys | Name   | Mode | Value |
+----------+------+------+--------+------+-------+
|      0   |  17  |  11  | GPIO 0 | IN   | Low   |
|      1   |  18  |  12  | GPIO 1 | IN   | Low   |
|      2   |  27  |  13  | GPIO 2 | IN   | Low   |
|      3   |  22  |  15  | GPIO 3 | IN   | Low   |
|      4   |  23  |  16  | GPIO 4 | IN   | Low   |
|      5   |  24  |  18  | GPIO 5 | IN   | Low   |
|      6   |  25  |  22  | GPIO 6 | IN   | Low   |
|      7   |   4  |   7  | GPIO 7 | IN   | Low   |
|      8   |   2  |   3  | SDA    | IN   | High  |
|      9   |   3  |   5  | SCL    | IN   | High  |
|     10   |   8  |  24  | CE0    | IN   | Low   |
|     11   |   7  |  26  | CE1    | IN   | Low   |
|     12   |  10  |  19  | MOSI   | IN   | Low   |
|     13   |   9  |  21  | MISO   | IN   | Low   |
|     14   |  11  |  23  | SCLK   | IN   | Low   |
|     15   |  14  |   8  | TxD    | ALT0 | High  |
|     16   |  15  |  10  | RxD    | ALT0 | High  |
|     17   |  28  |   3  | GPIO 8 | ALT2 | Low   |
|     18   |  29  |   4  | GPIO 9 | ALT2 | Low   |
|     19   |  30  |   5  | GPIO10 | ALT2 | Low   |
|     20   |  31  |   6  | GPIO11 | ALT2 | Low   |
+----------+------+------+--------+------+-------+

Solution 3:

Add -q 1 to the netcat command line:

while true; do 
  echo -e "HTTP/1.1 200 OK\n\n $(date)" | nc -l -p 1500 -q 1
done