The program allows the user to type in any linux command and then executes that command, such as "pwd" or "echo". The problem is that it should allow multiple commands to be typed in and executed at the same time, but it only allows one at a time currently. Please help fix it so it allows multiple commands to be typed and executed. Code:
#include
#include
#include
#include
#include
#include
void parse(char *line, char **argv)
{
while (*line != '\0') { /* if not the end of line */
while (*line == ' ' || *line == '\t' || *line == '\n')
*line++ = '\0'; /* replace white spaces with 0 */
*argv++ = line; /* save the argument position */
while (*line != '\0' && *line != ' ' &&
*line != '\t' && *line != '\n')
line++; /* skip the argument until ... */
}
*argv = '\0'; /* mark the end of argument list */
}
void execute(char **argv)
{
pid_t pid;
int status;
if ((pid = fork()) < 0) { /* fork a child process */
printf("*** ERROR: forking child process failed\n");
exit(1);
}
else if (pid == 0) { /* for the child process: */
if (execvp(*argv, argv) < 0) { /* execute the command */
printf("*** ERROR: exec failed\n");
exit(1);
}
}
else { /* for the parent: */
while (wait(&status) != pid) /* wait for completion */
;
}
}
void main(void)
{
char line[1024]; /* the input line */
char *argv[64]; /* the command line argument */
while (1) { /* repeat until done */
printf("Enter Shell Command -> "); /* display a prompt */
fgets(line, 1024, stdin); /* read in the command line */
printf("\n");
parse(line, argv); /* parse the line */
if (strcmp(argv[0], "exit") == 0) /* is it an "exit"? */
exit(0); /* exit if it is */
execute(argv); /* otherwise, execute the command */
}
}
This function receives a commend line argument list with the */ /* the first argument being cd and the next argument being the */ /* directory to change.