xsh_ps.c

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/* xsh_ps.c - xsh_ps */

#include <xinu.h>
#include <stdio.h>
#include <string.h>

/*------------------------------------------------------------------------
 * xsh_ps - shell command to print the process table
 *------------------------------------------------------------------------
 */
shellcmd xsh_ps(int nargs, char *args[])
{
    struct  procent *prptr;     /* pointer to process       */
    int32   i;          /* index into proctabl      */
    char *pstate[]  = {     /* names for process states */
        "free ", "curr ", "ready", "recv ", "sleep", "susp ",
        "wait ", "rtime"};

    /* For argument '--help', emit help about the 'ps' command  */

    if (nargs == 2 && strncmp(args[1], "--help", 7) == 0) {
        printf("Use: %s\n\n", args[0]);
        printf("Description:\n");
        printf("\tDisplays information about running processes\n");
        printf("Options:\n");
        printf("\t--help\t display this help and exit\n");
        return 0;
    }

    /* Check for valid number of arguments */

    if (nargs > 1) {
        fprintf(stderr, "%s: too many arguments\n", args[0]);
        fprintf(stderr, "Try '%s --help' for more information\n",
                args[0]);
        return 1;
    }

    /* Print header for items from the process table */

    printf("%3s %-16s %5s %4s %4s %10s %-10s %10s\n",
           "Pid", "Name", "State", "Prio", "Ppid", "Stack Base",
           "Stack Ptr", "Stack Size");

    printf("%3s %-16s %5s %4s %4s %10s %-10s %10s\n",
           "---", "----------------", "-----", "----", "----",
           "----------", "----------", "----------");

    /* Output information for each process */

    for (i = 0; i < NPROC; i++) {
        prptr = &proctab[i];
        if (prptr->prstate == PR_FREE) {  /* skip unused slots  */
            continue;
        }
        printf("%3d %-16s %s %4d %4d 0x%08X 0x%08X %8d\n",
            i, prptr->prname, pstate[(int)prptr->prstate],
            prptr->prprio, prptr->prparent, prptr->prstkbase,
            prptr->prstkptr, prptr->prstklen);
    }
    return 0;
}