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Design and implement a C/C++ program to implement a simple shell.

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PART1 Design and implement a C/C++ program to implement a simple shell. For a shell implementation, review APUE Ch9.9. Sample 1. The following sample program implements a simple shell to run one command. /* * a3p1shell1.c * simplest shell with a SIGINT signal handler. type EOF (^D) to exit. */ #include #include #include #include #include #include #include #include #include static void sig_int(int); char *getinput(char *buffer, size_t buflen) { printf(“$$ “); return fgets(buffer, buflen, stdin); } int main(int argc, char **argv) { char buf[1024]; pid_t pid; int status; if (signal(SIGINT, sig_int) == SIG_ERR) { fprintf(stderr, “signal error: %sn”, strerror(errno)); exit(1); } while (getinput(buf, sizeof(buf))) { buf[strlen(buf) – 1] = ‘ ‘; if((pid=fork()) == -1) { fprintf(stderr, “shell: can’t fork: %sn”, strerror(errno)); continue; } else if (pid == 0) { /* child */ execlp(buf, buf, (char *)0); fprintf(stderr, “shell: couldn’t exec %s: %sn”, buf, strerror(errno)); exit(EX_DATAERR); } if ((pid=waitpid(pid, &status, 0)) Sample 2. The following sample program is to run two commands in pipe (cmd1 | cmd2) where the two commands are hard-coded (cmd1 and cmd2). /* sample shell to handle two commands with pipe: ls | wc -l */ #include #include char *cmd1[] = { “/bin/ls”, 0 }; char *cmd2[] = { “/bin/wc”, “-l”, 0 }; void run2com(); int main(int argc, char **argv) { int pid, status; int fd[2]; pipe(fd); pid = fork(); if (pid == 0) { run2com(fd); exit(0); } else if (pid > 0) { while ((pid = wait(&status)) != -1) fprintf(stderr, “process %d exits with %dn”, pid, WEXITSTATUS(status)); } else…

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Assignment.docx