I dont want this

Applications Programming
1

Im creating a sort of shell, for my cybercafe
This will restrict my clients from accessing unwanted materials
so im programming a similar bash to

  1. to meet my goals
  2. to learn new things.

im creating it in C,
please have a look at the attachement.

i wish to avoid having a blank space when Enter is pressed.
i want it to react as bash does.
is there any means to catch the enter key before changing line?

2

Could you paste the code that you are using for this?

3

C,

This is a sample code that I wrote on a HP-UX 11.11 system. This prints a prompt and takes input. It does not act on the input, except when it receives exit - it exits.

#include<stdio.h>

int main() {
        char argarray[80];
        while(1) {
                fprintf(stdout,"! ");
                fgets(argarray,80,stdin);
                argarray[strlen(argarray)-1]='\0';
                if(!strcmp(argarray,"exit")){
                        break;
                }
                /*fprintf(stdout,"%s was input.\n",argarray);*/
        }
        exit(0);
}

You can uncomment the fprintf in the end to echo what was input.

4

im REwriting it at the moment,
AT THIS STAGE:
#include <stdio.h>
#include <sys/types.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>

struct stat s;

main() {

char c[100];
int desc,length_c;
char * _tmp =".myAI~";

desc = open( _tmp , O_CREAT | O_RDWR , 500 );
if ( desc < 0 ) {
perror("myAI ");
exit(0);
}

if (fork()==0) {
system("clear");
do {

printf\("myAI\\\\&gt;� "\); 
scanf\("%s",c\);
	
length_c=strlen\(c\);
lseek\(desc,0,sizeof\(char\)\);
write \(desc,c,length_c\);

/*
if \(strcmp\("machine",c\)==0\) \{
	   system\("echo $USER@\`hostname\`"\);
   system\("echo kernel : \`uname -r\`"\);
   system\("kde-config --version | grep KDE"\);
\}
else */if \(strcmp\("exit",c\)==0\) \{
   exit\(1\);
\}
else printf\("myAI: %s : command not found\\n",c\);

} while (c!=NULL);
exit(1);
}
wait(NULL);
}

THATS FOR SURE IT WONT WORK;
its only to give your an idea where i am

5

I think that this is where your problem lies. You can replace the scanf with the fgets that I am using in the code that I have posted in this thread.

6

Thanks it works.
at this stage im here :stuck_out_tongue:

#include <stdio.h>
#include <sys/types.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>

struct stat s;

main() {

 char c[100];
 int tmp_desc,length_c;
 char * _tmp = ".myAI~";
 char * _myAIrc = ".myAIrc";


 tmp_desc = open( _tmp , O_CREAT | O_RDWR , 500 );
 if ( tmp_desc < 0 ) {
    perror("myAI ");
    exit(0);
 }
 
 if (fork()==0) {
   system("clear");
   while(1) {
	
	fprintf(stdout,"!"); 
	fgets(c,100,stdin);
	c[strlen(c)-1]='\0';	
	length_c=strlen(c);
	lseek(tmp_desc,0,sizeof(char));
//	write (tmp_desc,c,length_c);
	
	/*
	if (strcmp("machine",c)==0) {
    	   system("echo $USER@`hostname`");
	   system("echo kernel : `uname -r`");
	   system("kde-config --version | grep KDE");
	}
	else */if(!strcmp(c,"exit")){
                        exit(0);
                }
	else printf("%s command not found\n",c);
	
   } while (c!=NULL);
	exit(1);
 }
 wait(NULL);
 
}
7

FWIW - there are restricted shells available.

It's fun to learn C I guess, except that http://freshmeat.net has 750+ unix shell projects. Because every CS major everywhere has to write one for a project. You can learn from what other folks did instead of completely re-inventing the wheel.