problem in string display

Step one must be to tidy up the listing a bit and fix some of the obvious errors.

#include<reg51.h>
#include<string.h>
#include<stdio.h>

#define lcd_data P1

sbit rs=P2^0;
sbit rw=P2^1;
sbit en=P2^2;

unsigned char n[]="hello";
unsigned char m[]="welcome rakesh";

void cmd_lcd(unsigned char);
void write_lcd(char);
void delay(unsigned int);

void lcd_int(void)
{
  cmd_lcd(0x38);
  cmd_lcd(0x0c);
  cmd_lcd(0x01);
  cmd_lcd(0x80);
}

void cmd_lcd(unsigned char x)
{
  lcd_data=x;
  rs=0;
  rw=0;
  en=1;
  delay(50);
  en=0;
}

void write_lcd(char s)
{
  lcd_data=s;
  rs=1;
  rw=0;
  en=1;
  delay(500);
  en=0;
}

void delay(unsigned int temp)
{
  unsigned int i,j;

  for(i=0;i<255;i++)
    for(j=0;j<temp;j++)
      ;
}

void main()
{
  unsigned int i;

  lcd_int();

  for (i=0;n[i]!=0;++i)
    write_lcd(n[i]);

  delay(500);

  cmd_lcd(0x01);
  delay(100);

  for (i=0;m[i]!=0;++i)
    write_lcd(m[i]);

  delay(100);

  for (;;)
    ;
}

Step one must be to tidy up the listing a bit and fix some of the obvious errors.

#include<reg51.h>
#include<string.h>
#include<stdio.h>

#define lcd_data P1

sbit rs=P2^0;
sbit rw=P2^1;
sbit en=P2^2;

unsigned char n[]="hello";
unsigned char m[]="welcome rakesh";

void cmd_lcd(unsigned char);
void write_lcd(char);
void delay(unsigned int);

void lcd_int(void)
{
  cmd_lcd(0x38);
  cmd_lcd(0x0c);
  cmd_lcd(0x01);
  cmd_lcd(0x80);
}

void cmd_lcd(unsigned char x)
{
  lcd_data=x;
  rs=0;
  rw=0;
  en=1;
  delay(50);
  en=0;
}

void write_lcd(char s)
{
  lcd_data=s;
  rs=1;
  rw=0;
  en=1;
  delay(500);
  en=0;
}

void delay(unsigned int temp)
{
  unsigned int i,j;

  for(i=0;i<255;i++)
    for(j=0;j<temp;j++)
      ;
}

void main()
{
  unsigned int i;

  lcd_int();

  for (i=0;n[i]!=0;++i)
    write_lcd(n[i]);

  delay(500);

  cmd_lcd(0x01);
  delay(100);

  for (i=0;m[i]!=0;++i)
    write_lcd(m[i]);

  delay(100);

  for (;;)
    ;
}

Is this the second step: Spoon feed the OP by giving ready-to-use code.

Just trying to get the thread out of the kindergarten loop.

Although harmless, including string.h and stdio.h is not necessary.

Thanx to you, one more attempt to activate a brain to start may turn into a failure.

PS: We are not consultants and hence should not provide ready code. :)

"Just trying to get the thread out of the kindergarten loop."

But the big issue is if the OP should learn enough to pass the final exam or just get working code and then fail even harder on next exercise.

What isn't known is basically black magic.
Copying code lines without understanding them results in programs like the one in the first post. Copying code lines from your post will just continue down that same route.

There really is a reason why teachers just don't hand out the final solution to problems and have the students duplicate it. It just fails so badly.

Point taken.

I was just kinda fed up with seeing messages arriving on my rss feed from this ridiculous and annoying thread. Seems my effort just fed the flame. Doh.

Although they were appreciated by the non-Please read the manual/fish catching factions here. Sometimes a clear illustration of how something should be done are a lot more helpful.

Fire fighting instructions for :
Hydrogen - Let it burn
Alkali Metals - Do not apply water