Hi,I want a C program for screen editor with following facilities i. Open an existing file ii. Create and Save the current file. iii. All cursor movements up, down, left, right arrow keys iv. Delete and backspace keys.
i have developed a program,but it doesn't work properly,Will you please correct it??I need it badly.
Following program runs partially,but it is not 100% correct.Please help me.I have developed it for Turbo C. ~~~~~
/* Experiment No.7 :Screen Editor : */
include <stdio.h>
include <conio.h>
include <string.h>
include <ctype.h>
define RIGHT 77
define LEFT 75
define UP 72
define DOWN 80
define DELETE 83
define BACKSPACE 8
define F1 59
define F2 60
define F3 61
int cx=1,cy=1,cxx=0,fchar=0,tchar=79; int nline=0; int fline=0,tline=0; int cline=0; /*************************************************** cx : X-Cordinate of the cursor cy : Y-Cordinate of the cursor cxx : position of the cursor in the current line in the file fchar,tchar : Only a portion of the line is displayed on the screen. fchar gives the left position and tchar gives the right position in the line. nline: Number of lines in the file fline,tline : In this program,21 lines of the file are displayed at a time. These lines are from fline to tline. cline: It gives the line number of the line on which the cursor is placed */
static char buffer[80][121];//The file may contain maximum of 80 lines, //each line may contain maximum of 118 characters int lengthof(int cline) ;//Gives the length of a line void displine(int cline);
void dispmenu() { int i; gotoxy(1,22); printf("---------------------------------------------------------------"); gotoxy(1,23); printf("F1 — Save F3- Exit"); gotoxy(1,24); printf("---------------------------------------------------------------"); }
int spaceline(int cline) //The current line may contain only white spaces { int j; for(j=0;j<120;j++) if(buffer[cline][j]!=' ' ) return(0); return(1); }
void display() //Display contents of the screen buffer { int i,j; clrscr(); for(i=fline;i<=tline;i++ ) { gotoxy(1,i+1-fline); for(j=fchar;j<=tchar;j++) { putchar(buffer[i][j]); } } dispmenu(); gotoxy(cx,cy); }
char read() //Read the next character { char x; x=getch(); if(x==0)//Control character x=getch(); return(x); } void Delete(int cline,int pos)//Delete the current character { int j; if(pos<0) return; for(j=pos+1;buffer[cline][j]!=0;j++)//Shift characters left by 1 place buffer[cline][j-1]=buffer[cline][j]; buffer[cline][j]=' ';
}
void deleteline() //Delete the current line { int i=0,j; if(nline>1) { for(i=cline+1;i<=tline;i++) strcpy(buffer[i-1],buffer[i]); nline--; if(cline>nline) { tline--; cy=cy-1; cx=1; cline=cline-1; } } display(); }
void insertline(int cline1,char x,int pos) { int i=0,j,length,l; char buff[180]; if(x==13)//Insert a new line, it breaks the line into two lines { for(i=nline;i>cline1;i--)//Shift lines by 1 position strcpy(buffer[i+1],buffer[i]); strcpy(buffer[cline1+1],buffer[cline1]+pos);//Line after Cursor position for(i=pos;i<=119;i++)//Fill spaces in the remaining portion buffer[cline1][i]=' '; buffer[cline1][120]=0;//End of text marker for(i=strlen(buffer[cline+1]);i<120;i++) //Fill spaces in the broken line buffer[cline1+1][i]=' '; buffer[cline1+1][120]=0; nline++; //Adjust coordinate variables cline++; tline++; cy=cy+1; cxx=0; cx=1; if(cy>21)//Adjustment for the last line of the screen { fline++; cy--; }
} else { for(i=118;i>=pos ;i--)//Shift right and insert the current character buffer[cline1][i+1]=buffer[cline1][i]; buffer[cline1][i+1]=x; } display(); gotoxy(cx,cy);//Position the cursor }
void save(char filename[])//Save the file { FILE *ptr; int i,j ; ptr=fopen(filename,"w"); if(ptr==NULL) { printf("\nCould not open the file"); getch(); }
for(i=0;i<nline;i++) { buffer[i][118]='\n'; buffer[i][119]=0; for(j=0;j<=119 && buffer[i][j]!=0;j++) putc(buffer[i][j],ptr); } fclose(ptr); }
void main() { static char filename[50]; FILE *ptr; int length,i; char x; buffer[0][0]=0;//Empty buffer clrscr(); printf("\nEnter the file name : "); gets(filename); ptr=fopen(filename,"r"); if(ptr==NULL) { ptr=fopen(filename,"w"); putc(' ',ptr); fclose(ptr); ptr=fopen(filename,"r"); }
if(ptr!=NULL)
{
while(!feof(ptr)) //Read the file in the screen buffer
{
tline++;
i=0;
fgets(buffer[nline],120,ptr);
while(buffer[nline][i]!='\n' && buffer[nline][i]!=0)
i++;
for(;i<119;i++)
buffer[nline][i]=' ';
buffer[nline][i]=0;
nline++;
}
}
fclose(ptr);
if(tline>20)
tline=20; //Maximum of 21 lines to be displayed
display();
gotoxy(cx,cy);
x=read(); //Read the next key
fchar=0;
tchar=lengthof(0) - 1;
if(tchar<0)
tchar=0;
if(tchar>79)
tchar=79;
while(x!=F3)
{
switch(x)
{
case F1:fclose(ptr);
save(filename);
break;
case UP:
if(cline>0)
if(cy>1 )//Scroll down
{
cy--;
cline--;
gotoxy(cx,cy);
}
else
{
fline--;
tline--;
cline--;
display();
gotoxy(cx,cy);
}
break;
case DOWN:
if(cline<nline)
if(cy<21 )//Scroll Up
{
cy++;
cline++;
gotoxy(cx,cy);
}
else
{
fline++;
tline++;
cline++;
display();
gotoxy(cx,cy);
}
break;
case RIGHT:
if(cxx<lengthof(cline))
if(cx<80 )
{
cx++;
cxx++;
gotoxy(cx,cy);
}
else
{ //Scroll left
cxx++;
fchar++;tchar++;
display();
}
break;
case LEFT:
if(cxx>0)
if(cx>1)
{
cx--;
cxx--;
gotoxy(cx,cy);
}
else
{ //Scroll right
cxx--;
fchar--;tchar--;
display();
}
break;
case DELETE:
if(cxx>0 || ! spaceline(cline))
{
tchar--;
Delete(cline,cxx);//Delete the current character
display();
gotoxy(cx,cy);
}
else
deleteline(cline);//Delete the current line
break;
case BACKSPACE:
if(cxx>0 )
{
tchar--;
Delete(cline,cxx-1);//Delete the previous character
cxx--;
if(cx>1)
cx--;
display();
gotoxy(cx,cy);
}
break;
case 13://Enter is pressed
insertline(cline,x,cxx);
break;
default:
if(isalnum(x)||ispunct(x)||isspace(x))
{
insertline(cline,x,cxx);
cx++;cxx++;
gotoxy(cx,cy);
}
break;
}
x=read();
}
}
int lengthof(int cline) { return(strlen(buffer[cline])); }
~~~~~
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