/* Name Chris Jackey * Date 10/5/09 * Class CPSC 410 */// FIRST - RENAME THIS FILE TO myps.c#include <stdio.h>#include <stdlib.h>#include <procfs.h>#include <sys/fcntl.h>#include <sys/types.h>#include <sys/stat.h>#include <dirent.h>#include <unistd.h>#include <string.h>int main (void) { DIR *directory; // pointer to the /proc directory. struct dirent *dirItem; // each directory item in /proc, these are all named after a system process id. char fname[25]; // character array to hold the complete path to psinfo for each directory in /proc. int fd; // reuseable file descriptor to reference the open psinfo file. struct psinfo ps; // a psinfo struct to hold the information read in from the psinfo file. // If the /proc file system can be opened capture a reference to it and continue // else exit cleanly. if(opendir("/proc") == NULL){ exit(1); } else{ directory = opendir("/proc"); } // You don't need the . and .. directories so bypass them. // Pretty print out your headers for each required stat (PID, PPID, CPU, ISIZE, RSIZE, CMD) printf("PID PPID CPU ISIZE RSIZE CMD\n"); /* Using the correct loop type -- remember, for loops are for when you know the number of * iterations and while loops are for when you don't know the number but do know the stop * condition -- loop through the directory doing the following on each iteration: * * 1) Set the fname to the complete path to psinfo [man sprintf]. * 2) open [man open(2)] the fname O_RDONLY, make sure to deal with error conditions if the file * cannot be opened. * 3) If the file is successfully opened, read [man read(2)] the file into the ps struct - note, * this is the heavy lifter and the trickiest line in the program. * 4) Once you have captured the psinfo in the ps struct then print out the variables of interest * using the C accessor operator, aka, the dot operator (.). * * * NOTE: the read function you are looking for is: * * ssize_t read(int fildes, void *buf, size_t nbyte); * * filedes is the file descriptor you captured when the open was successful. * void *buf is a pointer to the buffer to store the read data in. * size_t nbyte is the number of bytes to read from the file...read up on the sizeof function * * Your read function should look something like this * read(filedescriptor, an assignment to the address of your ps variable cast to a char *, the sizeof the struct psinfo) * */ readdir(directory); readdir(directory); while((dirItem = readdir(directory)) != NULL){ sprintf(fname, "/proc/%s/psinfo", dirItem->d_name); fd = open(fname, O_RDONLY); if(fd != -1){ read(fd, &ps, sizeof(struct psinfo)); char isize[8]; sprintf(isize, "%d", ps.pr_size); strcat(isize, "K"); char rsize[8]; sprintf(rsize, "%d", ps.pr_rssize); strcat(rsize, "K"); char cpu[8]; sprintf(cpu, "%.2f", (ps.pr_pctcpu / (float)0x800) * 100); strcat(cpu, "%"); printf("%-8u%-8u%-8s%-8s%-8s%s\n", ps.pr_pid, ps.pr_ppid, cpu, isize, rsize, ps.pr_psargs); } close(fd); } // Properly close the directory exit(1); // and exit the program.}