Unix program to use barcode input and cURL command on Raspberry Pi

Question

I want to build a program that will run in unix (raspberry pi) that will simply wait for input from a barcode reader and add the input into a cURL command, and then execute that command. The url is something like:

http://www.xyz.com/test/order/complete?barcode=123456789

where 123456789 would be the input.

Typically when a barcode is read with a scanner, it will add in a carriage return after it reads the code, meaning if you scanned it into a text editor, you would see the barcode and the cursor would be on the next line. I apologize for my ineptitude of programming - it's my parents fault ;)

I intend on running this program on startup of the Raspberry Pi instead of it running the desktop gui program, so some insight on that would be helpful as well.

Answer 1

Assuming your barcode reader sends the characters via keyboard input and does indeed put a CR after the barcode, I should think something like this would work. Compile w/gcc:

gcc -o runcurl runcurl.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc,char *argv[])

    {
    while (1)
        {
        char buf[256],syscmd[512];
        int i;

        /* Get next barcode */
        printf("Waiting for bar code [q=quit]:  ");
        if (fgets(buf,255,stdin)==NULL)
            break;

        /* Clean CR/LF off of string */
        for (i=0;buf[i]!='\0' && buf[i]!='\r' && buf[i]!='\n';i++);
        buf[i]='\0';

        /* q = quit */
        if (!strcmp(buf,"q"))
            break;

        /* Build into curl command */
        sprintf(syscmd,"curl \"http://www.xyz.com/test/order/complete?barcode=%s\"",buf);

        /* Execute--this will wait for command to complete before continuing. */
        system(syscmd);
        }
    return(0);
    }