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1 files changed, 0 insertions, 509 deletions

diff --git a/shlab-handout/tsh.c b/shlab-handout/tsh.c
deleted file mode 100644
index 7c2ea8d..0000000
--- a/shlab-handout/tsh.c
+++ /dev/null
@@ -1,509 +0,0 @@
-/* 
- * tsh - A tiny shell program with job control
- * 
- * <Put your name and login ID here>
- */
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <ctype.h>
-#include <signal.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <errno.h>
-
-/* Misc manifest constants */
-#define MAXLINE    1024   /* max line size */
-#define MAXARGS     128   /* max args on a command line */
-#define MAXJOBS      16   /* max jobs at any point in time */
-#define MAXJID    1<<16   /* max job ID */
-
-/* Job states */
-#define UNDEF 0 /* undefined */
-#define FG 1    /* running in foreground */
-#define BG 2    /* running in background */
-#define ST 3    /* stopped */
-
-/* 
- * Jobs states: FG (foreground), BG (background), ST (stopped)
- * Job state transitions and enabling actions:
- *     FG -> ST  : ctrl-z
- *     ST -> FG  : fg command
- *     ST -> BG  : bg command
- *     BG -> FG  : fg command
- * At most 1 job can be in the FG state.
- */
-
-/* Global variables */
-extern char **environ;      /* defined in libc */
-char prompt[] = "tsh> ";    /* command line prompt (DO NOT CHANGE) */
-int verbose = 0;            /* if true, print additional output */
-int nextjid = 1;            /* next job ID to allocate */
-char sbuf[MAXLINE];         /* for composing sprintf messages */
-
-struct job_t {              /* The job struct */
-    pid_t pid;              /* job PID */
-    int jid;                /* job ID [1, 2, ...] */
-    int state;              /* UNDEF, BG, FG, or ST */
-    char cmdline[MAXLINE];  /* command line */
-};
-struct job_t jobs[MAXJOBS]; /* The job list */
-/* End global variables */
-
-
-/* Function prototypes */
-
-/* Here are the functions that you will implement */
-void eval(char *cmdline);
-int builtin_cmd(char **argv);
-void do_bgfg(char **argv);
-void waitfg(pid_t pid);
-
-void sigchld_handler(int sig);
-void sigtstp_handler(int sig);
-void sigint_handler(int sig);
-
-/* Here are helper routines that we've provided for you */
-int parseline(const char *cmdline, char **argv); 
-void sigquit_handler(int sig);
-
-void clearjob(struct job_t *job);
-void initjobs(struct job_t *jobs);
-int maxjid(struct job_t *jobs); 
-int addjob(struct job_t *jobs, pid_t pid, int state, char *cmdline);
-int deletejob(struct job_t *jobs, pid_t pid); 
-pid_t fgpid(struct job_t *jobs);
-struct job_t *getjobpid(struct job_t *jobs, pid_t pid);
-struct job_t *getjobjid(struct job_t *jobs, int jid); 
-int pid2jid(pid_t pid); 
-void listjobs(struct job_t *jobs);
-
-void usage(void);
-void unix_error(char *msg);
-void app_error(char *msg);
-typedef void handler_t(int);
-handler_t *Signal(int signum, handler_t *handler);
-
-/*
- * main - The shell's main routine 
- */
-int main(int argc, char **argv) 
-{
-    char c;
-    char cmdline[MAXLINE];
-    int emit_prompt = 1; /* emit prompt (default) */
-
-    /* Redirect stderr to stdout (so that driver will get all output
-     * on the pipe connected to stdout) */
-    dup2(1, 2);
-
-    /* Parse the command line */
-    while ((c = getopt(argc, argv, "hvp")) != EOF) {
-        switch (c) {
-        case 'h':             /* print help message */
-            usage();
-	    break;
-        case 'v':             /* emit additional diagnostic info */
-            verbose = 1;
-	    break;
-        case 'p':             /* don't print a prompt */
-            emit_prompt = 0;  /* handy for automatic testing */
-	    break;
-	default:
-            usage();
-	}
-    }
-
-    /* Install the signal handlers */
-
-    /* These are the ones you will need to implement */
-    Signal(SIGINT,  sigint_handler);   /* ctrl-c */
-    Signal(SIGTSTP, sigtstp_handler);  /* ctrl-z */
-    Signal(SIGCHLD, sigchld_handler);  /* Terminated or stopped child */
-
-    /* This one provides a clean way to kill the shell */
-    Signal(SIGQUIT, sigquit_handler); 
-
-    /* Initialize the job list */
-    initjobs(jobs);
-
-    /* Execute the shell's read/eval loop */
-    while (1) {
-
-	/* Read command line */
-	if (emit_prompt) {
-	    printf("%s", prompt);
-	    fflush(stdout);
-	}
-	if ((fgets(cmdline, MAXLINE, stdin) == NULL) && ferror(stdin))
-	    app_error("fgets error");
-	if (feof(stdin)) { /* End of file (ctrl-d) */
-	    fflush(stdout);
-	    exit(0);
-	}
-
-	/* Evaluate the command line */
-	eval(cmdline);
-	fflush(stdout);
-	fflush(stdout);
-    } 
-
-    exit(0); /* control never reaches here */
-}
-  
-/* 
- * eval - Evaluate the command line that the user has just typed in
- * 
- * If the user has requested a built-in command (quit, jobs, bg or fg)
- * then execute it immediately. Otherwise, fork a child process and
- * run the job in the context of the child. If the job is running in
- * the foreground, wait for it to terminate and then return.  Note:
- * each child process must have a unique process group ID so that our
- * background children don't receive SIGINT (SIGTSTP) from the kernel
- * when we type ctrl-c (ctrl-z) at the keyboard.  
-*/
-void eval(char *cmdline) 
-{
-    return;
-}
-
-/* 
- * parseline - Parse the command line and build the argv array.
- * 
- * Characters enclosed in single quotes are treated as a single
- * argument.  Return true if the user has requested a BG job, false if
- * the user has requested a FG job.  
- */
-int parseline(const char *cmdline, char **argv) 
-{
-    static char array[MAXLINE]; /* holds local copy of command line */
-    char *buf = array;          /* ptr that traverses command line */
-    char *delim;                /* points to first space delimiter */
-    int argc;                   /* number of args */
-    int bg;                     /* background job? */
-
-    strcpy(buf, cmdline);
-    buf[strlen(buf)-1] = ' ';  /* replace trailing '\n' with space */
-    while (*buf && (*buf == ' ')) /* ignore leading spaces */
-	buf++;
-
-    /* Build the argv list */
-    argc = 0;
-    if (*buf == '\'') {
-	buf++;
-	delim = strchr(buf, '\'');
-    }
-    else {
-	delim = strchr(buf, ' ');
-    }
-
-    while (delim) {
-	argv[argc++] = buf;
-	*delim = '\0';
-	buf = delim + 1;
-	while (*buf && (*buf == ' ')) /* ignore spaces */
-	       buf++;
-
-	if (*buf == '\'') {
-	    buf++;
-	    delim = strchr(buf, '\'');
-	}
-	else {
-	    delim = strchr(buf, ' ');
-	}
-    }
-    argv[argc] = NULL;
-    
-    if (argc == 0)  /* ignore blank line */
-	return 1;
-
-    /* should the job run in the background? */
-    if ((bg = (*argv[argc-1] == '&')) != 0) {
-	argv[--argc] = NULL;
-    }
-    return bg;
-}
-
-/* 
- * builtin_cmd - If the user has typed a built-in command then execute
- *    it immediately.  
- */
-int builtin_cmd(char **argv) 
-{
-    return 0;     /* not a builtin command */
-}
-
-/* 
- * do_bgfg - Execute the builtin bg and fg commands
- */
-void do_bgfg(char **argv) 
-{
-    return;
-}
-
-/* 
- * waitfg - Block until process pid is no longer the foreground process
- */
-void waitfg(pid_t pid)
-{
-    return;
-}
-
-/*****************
- * Signal handlers
- *****************/
-
-/* 
- * sigchld_handler - The kernel sends a SIGCHLD to the shell whenever
- *     a child job terminates (becomes a zombie), or stops because it
- *     received a SIGSTOP or SIGTSTP signal. The handler reaps all
- *     available zombie children, but doesn't wait for any other
- *     currently running children to terminate.  
- */
-void sigchld_handler(int sig) 
-{
-    return;
-}
-
-/* 
- * sigint_handler - The kernel sends a SIGINT to the shell whenver the
- *    user types ctrl-c at the keyboard.  Catch it and send it along
- *    to the foreground job.  
- */
-void sigint_handler(int sig) 
-{
-    return;
-}
-
-/*
- * sigtstp_handler - The kernel sends a SIGTSTP to the shell whenever
- *     the user types ctrl-z at the keyboard. Catch it and suspend the
- *     foreground job by sending it a SIGTSTP.  
- */
-void sigtstp_handler(int sig) 
-{
-    return;
-}
-
-/*********************
- * End signal handlers
- *********************/
-
-/***********************************************
- * Helper routines that manipulate the job list
- **********************************************/
-
-/* clearjob - Clear the entries in a job struct */
-void clearjob(struct job_t *job) {
-    job->pid = 0;
-    job->jid = 0;
-    job->state = UNDEF;
-    job->cmdline[0] = '\0';
-}
-
-/* initjobs - Initialize the job list */
-void initjobs(struct job_t *jobs) {
-    int i;
-
-    for (i = 0; i < MAXJOBS; i++)
-	clearjob(&jobs[i]);
-}
-
-/* maxjid - Returns largest allocated job ID */
-int maxjid(struct job_t *jobs) 
-{
-    int i, max=0;
-
-    for (i = 0; i < MAXJOBS; i++)
-	if (jobs[i].jid > max)
-	    max = jobs[i].jid;
-    return max;
-}
-
-/* addjob - Add a job to the job list */
-int addjob(struct job_t *jobs, pid_t pid, int state, char *cmdline) 
-{
-    int i;
-    
-    if (pid < 1)
-	return 0;
-
-    for (i = 0; i < MAXJOBS; i++) {
-	if (jobs[i].pid == 0) {
-	    jobs[i].pid = pid;
-	    jobs[i].state = state;
-	    jobs[i].jid = nextjid++;
-	    if (nextjid > MAXJOBS)
-		nextjid = 1;
-	    strcpy(jobs[i].cmdline, cmdline);
-  	    if(verbose){
-	        printf("Added job [%d] %d %s\n", jobs[i].jid, jobs[i].pid, jobs[i].cmdline);
-            }
-            return 1;
-	}
-    }
-    printf("Tried to create too many jobs\n");
-    return 0;
-}
-
-/* deletejob - Delete a job whose PID=pid from the job list */
-int deletejob(struct job_t *jobs, pid_t pid) 
-{
-    int i;
-
-    if (pid < 1)
-	return 0;
-
-    for (i = 0; i < MAXJOBS; i++) {
-	if (jobs[i].pid == pid) {
-	    clearjob(&jobs[i]);
-	    nextjid = maxjid(jobs)+1;
-	    return 1;
-	}
-    }
-    return 0;
-}
-
-/* fgpid - Return PID of current foreground job, 0 if no such job */
-pid_t fgpid(struct job_t *jobs) {
-    int i;
-
-    for (i = 0; i < MAXJOBS; i++)
-	if (jobs[i].state == FG)
-	    return jobs[i].pid;
-    return 0;
-}
-
-/* getjobpid  - Find a job (by PID) on the job list */
-struct job_t *getjobpid(struct job_t *jobs, pid_t pid) {
-    int i;
-
-    if (pid < 1)
-	return NULL;
-    for (i = 0; i < MAXJOBS; i++)
-	if (jobs[i].pid == pid)
-	    return &jobs[i];
-    return NULL;
-}
-
-/* getjobjid  - Find a job (by JID) on the job list */
-struct job_t *getjobjid(struct job_t *jobs, int jid) 
-{
-    int i;
-
-    if (jid < 1)
-	return NULL;
-    for (i = 0; i < MAXJOBS; i++)
-	if (jobs[i].jid == jid)
-	    return &jobs[i];
-    return NULL;
-}
-
-/* pid2jid - Map process ID to job ID */
-int pid2jid(pid_t pid) 
-{
-    int i;
-
-    if (pid < 1)
-	return 0;
-    for (i = 0; i < MAXJOBS; i++)
-	if (jobs[i].pid == pid) {
-            return jobs[i].jid;
-        }
-    return 0;
-}
-
-/* listjobs - Print the job list */
-void listjobs(struct job_t *jobs) 
-{
-    int i;
-    
-    for (i = 0; i < MAXJOBS; i++) {
-	if (jobs[i].pid != 0) {
-	    printf("[%d] (%d) ", jobs[i].jid, jobs[i].pid);
-	    switch (jobs[i].state) {
-		case BG: 
-		    printf("Running ");
-		    break;
-		case FG: 
-		    printf("Foreground ");
-		    break;
-		case ST: 
-		    printf("Stopped ");
-		    break;
-	    default:
-		    printf("listjobs: Internal error: job[%d].state=%d ", 
-			   i, jobs[i].state);
-	    }
-	    printf("%s", jobs[i].cmdline);
-	}
-    }
-}
-/******************************
- * end job list helper routines
- ******************************/
-
-
-/***********************
- * Other helper routines
- ***********************/
-
-/*
- * usage - print a help message
- */
-void usage(void) 
-{
-    printf("Usage: shell [-hvp]\n");
-    printf("   -h   print this message\n");
-    printf("   -v   print additional diagnostic information\n");
-    printf("   -p   do not emit a command prompt\n");
-    exit(1);
-}
-
-/*
- * unix_error - unix-style error routine
- */
-void unix_error(char *msg)
-{
-    fprintf(stdout, "%s: %s\n", msg, strerror(errno));
-    exit(1);
-}
-
-/*
- * app_error - application-style error routine
- */
-void app_error(char *msg)
-{
-    fprintf(stdout, "%s\n", msg);
-    exit(1);
-}
-
-/*
- * Signal - wrapper for the sigaction function
- */
-handler_t *Signal(int signum, handler_t *handler) 
-{
-    struct sigaction action, old_action;
-
-    action.sa_handler = handler;  
-    sigemptyset(&action.sa_mask); /* block sigs of type being handled */
-    action.sa_flags = SA_RESTART; /* restart syscalls if possible */
-
-    if (sigaction(signum, &action, &old_action) < 0)
-	unix_error("Signal error");
-    return (old_action.sa_handler);
-}
-
-/*
- * sigquit_handler - The driver program can gracefully terminate the
- *    child shell by sending it a SIGQUIT signal.
- */
-void sigquit_handler(int sig) 
-{
-    printf("Terminating after receipt of SIGQUIT signal\n");
-    exit(1);
-}
-
-
-