Ok, I solved that, but I have this huge problem.
Heres my code...bit long:
#include<stdio.h>
#include<signal.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/wait.h>
#include<stdlib.h>
#include<fcntl.h>
#include<string.h>
#include<sys/stat.h>
#define SH_PROMPT ("GHOST")
#define ENDLINE ('\n')
#define PIPE_SPLIT ("|")
#define SPACE_SPLIT (" ")
//const char*argp[50],args[50];
int fdstdout, fdlog, fdstdin, fd;
int logFlag, fd;
const int lineLength=150;
int errFlag=0;
FILE *comlog;
//Functions//
int input_split(char a[], char *delimiter, char *argp[]);
void com_exec(char *arg[], int pargcount);
int intcom(char inp[]);
void readfile(char name[]);
int main()
{
char entcommand[6];
char excommand[3];
char ex[5]="exit";
char ent[6]="entry";
char inp[200]={'\0'};
char ext[3]="^D";
char *com[20];
char *arg[20];
char c,rb;
char *argp[50];
int k=0;
char *pipe;
int pargcount=0;
fdstdout=dup(1);
fdstdin=dup(0);
fdlog=open("output.log", O_RDWR|O_CREAT);
fd=open("buffer.txt", O_RDWR|O_CREAT);
entagain:
scanf("%s",entcommand);
while(strcmp(ent,entcommand)!=0)
{
printf("Command line interpreter not started\n\n");
fflush(stdout);
//fflush(stdin);
goto entagain;
}
entered:
if(strcmp(ent,entcommand)==0)
{
//printf("Welcome to (Ghost in a) Shell!\n"); //Initial prompt display
//printf("<%s>", SH_PROMPT);
fflush(stdout);
while(1) //Taking input string
{ printf("Enter command.");
rewind(stdin);
fflush(stdout);
c=getchar();
//dup2(fdstdout,1);
switch(c)
{
case ENDLINE: if(inp[0]=='\0')
{
dup2(fdstdout,1);
printf("<%s>", SH_PROMPT);
if(logFlag==1)
{
fdlog=open("output.log", O_RDWR|O_CREAT|O_APPEND, S_IRWXG);
dup2(fdlog,1);
}
} //If no input given
else
{
inp[k]='\0'; //For exiting the shell
if(strcmp(inp,ex)==0)
{ k=0;
goto exit;
}
else //Command execution
{
//printf("%s\n", inp);
//pipe="|" ;
if(logFlag==1)
{
fdlog=open("output.log", O_RDWR|O_CREAT|O_APPEND);
dup2(fdlog,1);
}
pargcount=input_split(inp,PIPE_SPLIT,argp);
com_exec(argp, pargcount);
}
//dup2(fdstdout,1);
//printf("<%s>", SH_PROMPT);
//if(logFlag==1)
//{
// fdlog=open("output.log", O_RDWR|O_CREAT|O_APPEND); //
// dup2(fdlog,1);
//}
close(fd);
dup2(fdstdout,1);
fflush(stdout);
k=0;
printf("<%s>", SH_PROMPT);
if(logFlag==1)
{
comlog=fopen("command.log", "a");
fwrite(inp,1,strlen(inp),comlog);
fclose(comlog);
}
memset(inp,'\0',200);
rb=getchar();
}
break;
default : inp[k++]=c; //writing the command string
break;
}
}
}
exit:
scanf("%s", excommand);
while (strcmp(excommand,"entry")!=0)
{
printf("Shell has exited. \n");
scanf("%s", excommand);
}
fflush(stdout);
//rb=getchar();
goto entered;
return 0;
}
//Function for seperating the arguments, returns argument count//
int input_split(char inp[], char *delimiter, char *argp[])
{
int i=0;
int j=0;
char *temp;
if(strlen(inp)==0)
{return 0;}
else{
temp=strtok (inp,delimiter);
//Stores the seperate commands/arguments into an array of pointers//
while(temp!=NULL)
{
argp[i++]=temp;
temp=strtok (NULL,delimiter);
}
return i;
}
}
//Function for executing the commands//
void com_exec(char *arg[], int pargcount)
{
if(pargcount==0)
{
printf("Wtf");
//exit(0);
}
else
{
char *args[50];
char *delim;
int sargcount, j=0;
long tbsz;
pid_t pid1,pid2;
if(pargcount==1) //Implies either single command with arguments or internal command, i.e, no pipes
{
delim=" ";
sargcount=input_split(arg[0],SPACE_SPLIT,args);
if(!intcom(args[0]))
{
pid1=fork();
if(!pid1) //child process executing//
{
execvp(args[0],args);
printf("EXECVP failed to execute.\n");
}
else if(pid1>0)
{
waitpid(pid1,NULL,0); //Parent process executing//
}
else {printf("Child unborn.\n");}
}
}
else //Multiple commands with pipes given//
{
//int fd;
for(j=0;j<pargcount;j++)
{
if(j==0)
{
//fd=open("buffer.txt", O_RDWR|O_CREAT, S_IRWXG); //First argument
tbsz=getdtablesize();
//close(fd);
dup2(fd,1);
}
else if((j+1)==pargcount)
{
fd=open("buffer.txt", O_RDONLY); //Last argument
//close(fd);
dup2(fd,0);
dup2(fdstdout,1);
}
else
{
fd=open("buffer.txt",O_RDWR); //In between arguments
//close(fd);
dup2(fd,1);
dup2(fd,0);
}
delim=" ";
sargcount=input_split(arg[j],delim,args);
pid1=fork();
if(!pid1) //child process executing
{
close(fd);
execvp(args[0],args);
printf("EXECVP failed to execute.\n");
}
else if(pid1>0)
{
waitpid(pid1,NULL,0);
}
else {printf("Child unborn.\n");}
}
}
}
}
int intcom(char inp[])
{
if (strcmp(inp,"log")==0)
{
printf("Now logging data \n");
logFlag = 1;
//close(fdlog);
dup2(fdlog,1);
return (1);
}
else if (strcmp(inp,"unlog")==0)
{
logFlag = 0;
//close(fdstdout);
dup2(fdstdout,1);
printf("Logging no more. \n");
return (1);
}
else if (strcmp(inp,"viewcmd")==0)
{
// Implement Code for viewcmd
printf("Command Log \n");
readfile("command.log");
return (1);
}
else if (strcmp(inp,"viewoutlog")==0)
{
// Implement Code for viewoutlog
printf("Output Log \n");
readfile("output.log");
return (1);
}
else if (strcmp(inp,"changedir")==0)
{
// Implement Code for changedir
}
else
return (0);
}
void readfile(char name[])
{
FILE *fp;
char line[lineLength];
fp = fopen(name,"r");
while(fgets(line,sizeof(line),fp))
{
printf("%s",line);
}
fclose(fp);
}
SOme redundant things because I was error checking.
Thing is after it runs the first time, getchar() keeps taking in a character without me typing, and this keeps going on until it goes out of memory and hits a segmentation fault.
Why is getchar() taking a character without giving the prompt?