124 lines
3.1 KiB
C
124 lines
3.1 KiB
C
#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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/**************************************************************************
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* Authors: Gary Fleming, Amber McCloughan
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* Class: CIS452 - Operating Systems Concepts
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* Professor: Dr. Greg Wolffe
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* Date: 4/19/2019
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*
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* Program that mimics the ln command's basic functionality.
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* You can create soft links or hard links using this program.
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*
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* Arguments
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* -------------------------------------------------------------------------
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* -s : Specifies we're creating a soft link.
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* [source] : Input a file that will be linked to. MUST COME
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* FIRST!
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* [destination] : Input a file name for the new link file. MUST
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* COME LAST!
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***************************************************************************/
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#define MAX_BUF_SIZE 102
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/**
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* Main function of the program. Takes in
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* three possible arguments: -s, [source],
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* and [destination].
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*
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* @param argc, number of arguments.
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* @param argv, the actual arguments.
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*/
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int main(int argc, char *argv[])
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{
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// Tracking if we're doing a symlink.
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int sFlag = 0;
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// For counting arguments.
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int numCount = 0;
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// Used in the for loop when checking arguments.
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int i;
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// Buffer for link source.
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char *source = malloc(MAX_BUF_SIZE * sizeof(char));
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// Buffer for the new link.
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char *dest = malloc(MAX_BUF_SIZE * sizeof(char));
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// Reading the program arguments.
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for (i = 1; i < argc; i++)
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{
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// If we found the -s flag.
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if (!strcmp(argv[i], "-s"))
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{
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sFlag = 1;
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}
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// For file path arguments.
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else
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{
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// For the source file.
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if (numCount == 0)
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{
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strcpy(source, argv[i]);
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numCount++;
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}
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// For the destination file (link).
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else if (numCount == 1)
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{
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strcpy(dest, argv[i]);
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numCount++;
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}
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// There must have been too many arguments.
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else
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{
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printf("Too many arguments provided!\n");
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free(source);
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free(dest);
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return -1;
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}
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}
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}
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// There must have not been enough arguments.
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if (numCount < 2)
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{
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printf("Not enough arguments provided!\n");
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free(source);
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free(dest);
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return -1;
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}
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// If we're dealing with a hard link.
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if (sFlag == 0)
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{
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if (link(source, dest) < 0)
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{
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perror("Huh? There is... ");
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free(source);
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free(dest);
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return -1;
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}
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}
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// Otherwise, we're dealing with a soft link.
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else
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{
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if (symlink(source, dest) < 0)
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{
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perror("Huh? There is... ");
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free(source);
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free(dest);
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return -1;
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}
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}
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// Freeing resources.
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free(source);
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free(dest);
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// Goodbye (for the semester)!
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return 0;
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} |