Bash ping script with LCD error message errors - c

Question

I am working in Debian and I am trying to write a script that will ping a host (192.168.10.30) every 10 seconds.
Whenever the ping is not successful, I want to have the message "VPN Lost" be displayed on my LCD screen. Once the ping is successful again the "VPN Lost" message will disappear from my LCD screen, and the screen will display "STS300".
The code below keeps giving me an error when I try to compile it, and I do not understand why. (The code compiles fine, but once I added in the code for the ping it won't compile). The code that is giving me trouble is between the lines lcd_command(LINE_3); and lcd_command(LINE_4);
I am fairly new to this...
The errors I am getting are...
lcdSignal.c: In function 'main': lcdSignal.c:190:10: error: expected
'(' before 'true'
lcdSignal.c:190:10: error: 'true' undeclared (first use in this
function)
lcdSignal.c:190:10: note: each undeclared identifier is reported only
once for each function it appears in
lcdSignal.c:191:3: error: 'ping' undeclared (first use in this
function)
lcdSignal.c:191:12: error: too many decimal points in number
lcdSignal.c:191:9: error: 'c1' undeclared (first use in this function)
lcdSignal.c:191:12: error: expected ';' before numeric constant
lcdSignal.c:192:3: error: expected 'while' before 'lcd_writechars'
lcdSignal.c:193:7: error: expected '(' before '[' token
lcdSignal.c:193:12: error: '$' undeclared (first use in this function)
lcdSignal.c:193:19: error: unknown type name 'then'
lcdSignal.c:194:18: error: expected declaration specifiers or '...'
before string constant
lcdSignal.c:195:3: error: 'fi' undeclared (first use in this function)
lcdSignal.c:196:9: error: expected ';' before numeric constant
If someone could help me, I would greatly appreciate it!!!
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include "evgpio.h"
#include "STSConfig.h" // This file is where the strings are modified
void lcd_init(void);
void lcd_wait(void);
void lcd_command(uint16_t);
void lcd_writechars(unsigned char *dat);
// These are microsecond delays
#define SETUP 1
#define PULSE 2
#define HOLD 1
#define LINE_1 0x80 // beginning position of LCD line 1
#define LINE_2 0xC0 // beginning position of LCD line 2
#define LINE_3 0x94 // beginning position of LCD line 3
#define LINE_4 0xD4 // beginning position of LCD line 4
#define LCD_D0 74
#define LCD_D1 75
#define LCD_D2 72
#define LCD_D3 73
#define LCD_D4 70
#define LCD_D5 71
#define LCD_D6 68
#define LCD_D7 69
#define LCD_EN 64
#define LCD_WR 65
#define LCD_RS 66
#define LCD_BIAS 67
void lcd_write(uint8_t out)
{
evsetdata(LCD_D0, out & (1 << 0));
evsetdata(LCD_D1, out & (1 << 1));
evsetdata(LCD_D2, out & (1 << 2));
evsetdata(LCD_D3, out & (1 << 3));
evsetdata(LCD_D4, out & (1 << 4));
evsetdata(LCD_D5, out & (1 << 5));
evsetdata(LCD_D6, out & (1 << 6));
evsetdata(LCD_D7, out & (1 << 7));
}
void lcd_ddr(uint8_t out)
{
evsetddr(LCD_D0, out & (1 << 0));
evsetddr(LCD_D1, out & (1 << 1));
evsetddr(LCD_D2, out & (1 << 2));
evsetddr(LCD_D3, out & (1 << 3));
evsetddr(LCD_D4, out & (1 << 4));
evsetddr(LCD_D5, out & (1 << 5));
evsetddr(LCD_D6, out & (1 << 6));
evsetddr(LCD_D7, out & (1 << 7));
}
uint8_t lcd_read()
{
uint8_t out = 0;
out |= (evgetin(LCD_D0) << 0);
out |= (evgetin(LCD_D1) << 1);
out |= (evgetin(LCD_D2) << 2);
out |= (evgetin(LCD_D3) << 3);
out |= (evgetin(LCD_D4) << 4);
out |= (evgetin(LCD_D5) << 5);
out |= (evgetin(LCD_D6) << 6);
out |= (evgetin(LCD_D7) << 7);
return out;
}
void lcd_enpulse()
{
usleep(SETUP);
evsetdata(LCD_EN, 1);
usleep(PULSE);
evsetdata(LCD_EN, 0);
usleep(HOLD);
}
void lcd_init(void)
{
evgpioinit();
// Data lines to inputs, control lines to outputs
lcd_ddr(0x0);
evsetddr(LCD_EN, 1);
evsetddr(LCD_RS, 1);
evsetddr(LCD_WR, 1);
// Set LCD_EN and LCD_RS low
evsetdata(LCD_EN, 0);
evsetdata(LCD_RS, 0);
// Set LCD_WR high
evsetdata(LCD_WR, 1);
usleep(15000);
lcd_command(0x38); // two rows, 5x7, 8 bit
usleep(4100);
lcd_command(0x38); // two rows, 5x7, 8 bit
usleep(100);
lcd_command(0x38); // two rows, 5x7, 8 bit
lcd_command(0x6); // cursor increment mode
lcd_wait();
//lcd_command(0x1); // clear display
// lcd_wait();
// lcd_command(0xc); // display on, blink off, cursor off
// lcd_wait();
lcd_command(0x2); // return home
evsetddr(LCD_BIAS, 1);
evsetdata(LCD_BIAS, 0);
}
void lcd_wait(void)
{
uint8_t in;
int i, dat, tries = 0;
lcd_ddr(0x0);
do {
// step 1, apply only RS & WR
evsetdata(LCD_RS, 0);
evsetdata(LCD_WR, 1); // low for write
lcd_enpulse();
usleep(1);
} while (in & 0x80 && tries++ < 5);
}
void lcd_command(uint16_t cmd)
{
lcd_ddr(0xff);
lcd_write(cmd);
evsetdata(LCD_WR, 0);
evsetdata(LCD_RS, 0);
lcd_enpulse();
}
void lcd_writechars(unsigned char *dat)
{
int i;
do {
lcd_wait();
lcd_ddr(0xff);
evsetdata(LCD_RS, 1);
evsetdata(LCD_WR, 0); // active low
lcd_write(*dat++);
lcd_enpulse();
} while (*dat);
}
int main(int argc, char *argv[])
{
char *temp = argv[1];
float sigStn = atof(temp);
float numBuf = (((sigStn-(-120))/(-70-(-120)))*100);
char buf[48];
if (numBuf >=9 && numBuf<=99) {
snprintf(buf, sizeof(buf), " Signal= %0.0f",numBuf);
strcat(buf,"% ");
} else {
snprintf(buf, sizeof(buf), " Signal= %0.0f",numBuf);
strcat(buf,"% ");
}
lcd_init();
lcd_command(LINE_1);
lcd_writechars(STS);
lcd_command(LINE_2);
if (numBuf > 100)
lcd_writechars(" Signal= 100% ");
else if(numBuf<0){
lcd_writechars(" Reconnecting ");
// lcd_writechars(" Signal = 0% ");
} else
lcd_writechars(buf);
lcd_command(LINE_3);
{while true; do
ping -c1 192.168.10.30 2>&1 /dev/null; //VPN IP
lcd_writechars("STS300");}
{if [[ ! $? ]]; then
lcd_writechars("VPN Lost");
fi;
sleep 10;
}
lcd_command(LINE_4);
lcd_writechars(BBPN);
return;
while (!feof(stdin)) {
unsigned char buf[512];
int i = 0;
lcd_wait();
if (i) {
// XXX: this seek addr may be different for different
// LCD sizes! -JO
lcd_command(0xa8); // set DDRAM addr to second row
} else
lcd_command(0x2); // return home
i = i ^ 0x1;
if (fgets(buf, sizeof(buf), stdin) != NULL) {
unsigned int len;
buf[0x27] = 0;
len = strlen(buf);
if (buf[len - 1] == '\n') buf[len - 1] = 0;
lcd_writechars(buf);
}
}
return 0;
}

Answer 1

The following lines of code in your program aren't C at all. They look like a fragment of shell script:
lcd_command(LINE_3);
{while true; do
ping -c1 192.168.10.30 2>&1 /dev/null; //VPN IP
lcd_writechars("STS300");}
{if [[ ! $? ]]; then
lcd_writechars("VPN Lost");
fi;
sleep 10;
}
This won't work. Rewrite this code in C. (The system() function may be helpful.)