How to grep a a string pattern from a socket in bash

Question

i want to create a bash script that grep a specific value from a socket

The data, i get from the socket is like this:

$GPGSV,4,3,14,16,19,14,30,,,25*7834128.000,V,N*4D
$GPRMC,134129.000,V,5309.2672,N,00811.8483,E,0F
$GPGGA,1341299,99.9*09

I want to get the information between $GPRMC, and 000

can i use the nc-command with sed for this?

Answer 1

You can use awk

data=$(nc localhost 12000 | awk -F"[.,]" '/GPRMC/ {print $2}')
echo $data
134129

This will connect to port 12000 on localhost and if it gets data automatically from this, you can parse it trough awk sed or other program

Answer 2

nc -l  | sed -n 's/^\$GPRMC\(.*\)000.*/\1/p'

with only a grep but need certainly to specify a more exact pattern limit (like 000, to avoid any string longer if another 000 is in the string) If only first 000 is the limit, sed action need to change a bit

Answer 3

If the output of nc -l is not large and you want the value in a variable, use a read loop:

while IFS=., read match GPRMC _; do
    [[ $match = '$GPRMC' ]] && break
done < <(nc -l)
# Value is in "$GPRMC"

Note: if no matching line is found, the last line output by nc -l will be used.

Answer 4

You could try something like :

[ ~]$ cat test.txt 
$GPGSV,4,3,14,16,19,14,30,,,25*7834128.000,V,N*4D
$GPRMC,134129.000,V,5309.2672,N,00811.8483,E,0F
$GPGGA,1341299,99.9*09
[ ~]$ sed -n 's/.*\$GPRMC,\([0-9]*\)\.000.*/\1/p' test.txt
134129

You could use awk too :

[ ~]$ awk -F "[,.]" '($0 ~ "\\$GPRMC,.*\\.000"){print $2}' test.txt 
134129

If you want to catch the result of a command into a variable :

[ ~]$ var=$(cmd)
[ ~]$ var=`cmd`

Answer 5

int x = 0, cmp = 0;
    char str[]="$GPRMC,220516,A,5133.82,N,00042.24,W,173.8,231.8,251114,004.2,W*70";
    char *str1;

    char url[300];
    strcpy (url,"?");


    str1 = strtok(str, ",");
    cmp = strcmp (str1, &"$GPRMC");
    if(cmp ==  0)
    {
        while (x < 12)
        {
            str1 = strtok(NULL, ",");
            if (str1 == NULL)
            {
                x++;
            }
            else
            {
                x++;
                switch(x) 
                {
                    case 1:
                        strcat (url,"tm=");
                        strcat (url,str1);
                        break;
                    case 3:
                        strcat (url,"&lt=");
                        strcat (url,str1);
                        break;
                    case 5:
                        strcat (url,"&ln=");
                        strcat (url,str1);
                        break;
                    case 9:
                        strcat (url,"&dt=");
                        strcat (url,str1);
                        break;
                }
            }
        }
        strcat (url,"&fl=0");
        strcat (url,"&en=0");
        printf("%i: %s\n", x, url);
    }
    getch();

Answer 6

Would

nc -l | grep "GPRMC" | sed "s/.GPRMC,//" | sed "s/.000.*//

work for you?