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  1. /**
  2. UNIX Shell Project
  3.  
  4. Sistemas Operativos
  5. Grados I. Informatica, Computadores & Software
  6. Dept. Arquitectura de Computadores - UMA
  7.  
  8. Some code adapted from "Fundamentos de Sistemas Operativos", Silberschatz et al.
  9.  
  10. To compile and run the program:
  11.    $ gcc Shell_project.c job_control.c -o Shell
  12.    $ ./Shell          
  13. 	(then type ^D to exit program)
  14.  
  15. **/
  16.  
  17. #include "job_control.h"   // remember to compile with module job_control.c 
  18.  
  19. #define MAX_LINE 256 /* 256 chars per line, per command, should be enough. */
  20.  
  21. // -----------------------------------------------------------------------
  22. //                            MAIN          
  23. // -----------------------------------------------------------------------
  24.  
  25. int main(void)
  26. {
  27. 	char inputBuffer[MAX_LINE]; /* buffer to hold the command entered */
  28. 	int background;             /* equals 1 if a command is followed by '&' */
  29. 	char *args[MAX_LINE/2];     /* command line (of 256) has max of 128 arguments */
  30. 	// probably useful variables:
  31. 	int pid_fork, pid_wait; /* pid for created and waited process */
  32. 	int status;             /* status returned by wait */
  33. 	enum status status_res; /* status processed by analyze_status() */
  34. 	int info;				/* info processed by analyze_status() */
  35.  
  36. 	while (1)   /* Program terminates normally inside get_command() after ^D is typed*/
  37. 	{   		
  38. 		printf("COMMAND->");
  39. 		fflush(stdout);
  40. 		get_command(inputBuffer, MAX_LINE, args, &background);  /* get next command */
  41.  
  42. 		if(args[0]==NULL) continue;   // if empty command
  43.  
  44.  
  45.  		pid_fork = fork();   // creamos un proceso hijo
  46.  
  47.  		if (pid_fork == 0) {//Proceso hijo
  48.  			execvp(args[0], args)
  49.  			perror("Fallo de exec");
  50. 			exit(EXIT_FAILURE);
  51.  		}
  52.  		else{ //proceso padre
  53.  			if(background == 0){
  54.  				pid_wait=waitpid(pid_fork);
  55.  			}else{
  56.  				continue;
  57.  			}
  58.  			printf("Motivo de terminación:  %s\n",status_strings[status]);	
  59.  
  60.  		}
  61.  
  62.  
  63. 		/* the steps are:
  64. 			 (1) fork a child process using fork()
  65.  
  66. 			 (2) the child process will invoke execvp()
  67. 			 (3) if background == 0, the parent will wait, otherwise continue 
  68. 			 (4) Shell shows a status message for processed command 
  69. 			 (5) loop returns to get_commnad() function
  70. 		*/
  71.  
  72. 	} // end while
  73. }
  74.  
Compilation error #stdin compilation error #stdout 0s 0KB
comments (?)
stdin
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Standard input is empty
compilation info 
prog.c:17:77: fatal error: job_control.h: No such file or directory
compilation terminated.
stdout
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Standard output is empty
https://ideone.com/NVMOVE
language:
C (gcc 8.3)
created:
9 years ago
visibility:
public

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