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contents.c
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contents.c
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/*
CPE 357 Asgn4
Author: Dylan Baxter (dybaxter), Van Park (vpark05)
File: contents.c
Description: This file contains functions used to print contents
of a TAR file
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <limits.h>
#include <errno.h>
#include <utime.h>
#include <time.h>
#include <string.h>
#include <sys/time.h>
#include "contents.h"
#include "extr_helper.h"
void printContents(char **fileNames,int pathcount,
char *archive, unsigned int options){
/* Takes in a given file name, archive, and option mask.
* Prints the contents of the archive
*/
int arch;
/* Open the archive */
if (-1==(arch = open(archive, O_RDONLY, 0666))){
perror(archive);
exit(EXIT_FAILURE);
}
/* Initialize variables */
char buffer[512];
struct Header *head;
int numblocks = 0;
int readsize = 0;
int checkVal = 0;
int endblock = 0;
int i;
/*Read through the entire archive to find what you are looking for */
while((readsize = read(arch, buffer, 512)) > 0){
/* If a header is encountered set the header pointer */
if (numblocks == 0){
head = (struct Header *)(buffer);
checkVal = checksum(head);
if(checkVal == -1){
fprintf(stderr,"INVALID HEADER\n");
return;
}
if (checkVal == 0){
endblock++;
if(endblock < 1){
return;
}
}
/* Get the size and check how many blocks
* are required for the file
*/
int size = unoctal(head->size);
if((size % 512) == 0){
numblocks = size / 512;
}
else{
numblocks = (size / 512) + 1;
}
char fname[257] = {0};
char delim[2] = "/\0";
for(i=0;i<155;i++){
if(head->prefix[i] != '\0'){
fname[i] = head->prefix[i];
}
else{
break;
}
}
if(strlen(fname)){
strcat(fname, delim);
}
strncat(fname, head->name, 100);
/*Determine whether to write*/
/*Find type*/
int extractFlag = 0;
for(i=0;i<pathcount;i++){
if (!(strcmp(fname, fileNames[i]))
|| checkpre(fileNames[i], fname)){
extractFlag = 1;
break;
}
}
if((options & ALLFLAG)){
extractFlag = 1;
}
if (options & VERBOSE){
/* Check if verbose option is set */
if(extractFlag){
/* Check if you run into a file that you want to print */
if(strlen(fname)){
int size = unoctal(head->size);
time_t mtime = unoctal(head->mtime);
mode_t mode = unoctal(head->mode);
char buf[11] = {'\0'};
char timBuf[18];
permissions(mode, buf, head);
strftime(timBuf, 18, "%Y-%m-%d %H:%M",
localtime(&mtime));
/* Convert the mode into a string
* Convert the time_t into a readable format
*/
printf("%s %s/%s %14d %s %s\n", buf, head->uname,
head->gname, size, timBuf, fname);
}
}
}
else{
if(extractFlag){
/*If verbose is not set just print the name of the file */
if(strlen(fname)){
printf("%s\n", fname);
}
}
}
}
else{
numblocks--;
}
}
}
void permissions(mode_t mode, char* perm, struct Header* head){
/*Takes in the mode of the file, a buffer to input into and the header
* from the archive. Converts the mode into a string representation
* for easier readability.
*/
int i;
for(i=0;i<11;i++){
perm[i] = '-';
}
/* Check typeflag to determine the first char of the string */
if ((head->typeflag) == '5'){
perm[0] = 'd';
}
if ((head->typeflag) == '2'){
perm[0] = 'l';
}
/* Check all user permissions */
if (mode & S_IRUSR){
perm[1] = 'r';
}
if (mode & S_IWUSR){
perm[2] = 'w';
}
if (mode & S_IXUSR){
perm[3] = 'x';
}
/* Check all group permissions */
if (mode & S_IRGRP){
perm[4] = 'r';
}
if (mode & S_IWGRP){
perm[5] = 'w';
}
if (mode & S_IXGRP){
perm[6] = 'x';
}
/* Check all other permissions */
if (mode & S_IROTH){
perm[7] = 'r';
}
if (mode & S_IWOTH){
perm[8] = 'w';
}
if (mode & S_IXOTH){
perm[9] = 'x';
}
/* NULL terminate the string */
perm[10] = 0;
}