*** 3000shell.c	2021-01-22 00:57:39.000000000 -0500
--- 3000shell-pipe.c	2025-02-22 20:02:17.463704228 -0500
***************
*** 27,32 ****
--- 27,34 ----
  #define COMM_SIZE 32
  
  const char *proc_prefix = "/proc";
+ int pipeline = 0;
+ 
  
  void parse_args(char *buffer, char** args, 
                  size_t args_size, size_t *nargs)
***************
*** 249,258 ****
          }
  }
  
  void prompt_loop(char *username, char *path, char *envp[])
  {
          char buffer[BUFFER_SIZE];
!         char *args[ARR_SIZE];
          
          int background;
          size_t nargs;
--- 251,297 ----
          }
  }
  
+ void run_programs(char *args1, char *args2, char *path, char *envp[])
+ {
+ 	pid_t pid1, pid2;
+ 	int pipefd[2], *ret_status = NULL;
+ 	char buffer[BUFFER_SIZE];
+ 	FILE *a, *b;
+ 	char c;
+ 
+ 	a = popen(args1, "r");
+ 	b = popen(args2, "w");
+ 
+ 	printf("a=%s\n", args1);
+ 	printf("b=%s\n", args2);
+ 
+  	while ((c = fgetc(a)) != EOF)
+  	{
+ 		fputc(c, b);
+  	}
+ 
+ 	pclose(a);
+ 	pclose(b);
+ 
+ }
+ 
+ char **split_pipeline(char *buffer)
+ {	
+ 	static char *stages[2];
+ 	if ((strchr(buffer, '|') != strrchr(buffer, '|')) || (NULL == strchr(buffer, '|')))
+ 		return NULL;
+ 	char *buffer2 = strdup(buffer);
+ 	stages[0] = strtok(buffer2, "|");
+ 	stages[1] = strtok(NULL, "|");
+ 	pipeline = 1;
+ 	return stages;	
+ }
+ 
  void prompt_loop(char *username, char *path, char *envp[])
  {
          char buffer[BUFFER_SIZE];
! 	char backup[BUFFER_SIZE];
!         char *args[ARR_SIZE], *args2[ARR_SIZE];
          
          int background;
          size_t nargs;
***************
*** 269,276 ****
                          printf("\n");
                          exit(0);
                  }
!                 
!                 parse_args(buffer, args, ARR_SIZE, &nargs); 
                  
                  if (nargs==0) continue;
                  
--- 308,324 ----
                          printf("\n");
                          exit(0);
                  }
! 
! 		pipeline = 0;
!         
! 		char **l = split_pipeline(buffer);
! 		if (l != NULL){	
! 		printf("stage1=%s\n", l[0]);
! 		printf("stage2=%s\n", l[1]);
! 		strcpy(backup, l[0]);
! 		}
! 		
! 		parse_args(l==NULL?buffer:l[0], args, ARR_SIZE, &nargs); 
                  
                  if (nargs==0) continue;
                  
***************
*** 304,311 ****
                                  break;
                          }
                  }
!                 
!                 run_program(args, background, stdout_fn, path, envp);
          }    
  }
  
--- 352,363 ----
                                  break;
                          }
                  }
!         
! 		if (pipeline) {
! 			run_programs(backup, l[1], path, envp);
! 	}
! 		else        
!                 	run_program(args, background, stdout_fn, path, envp);
          }    
  }