src/world/usr.bin/shred/src/shred.c

296 lines
7.3 KiB
C

/*
*----------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <jeang3nie@HitchHiker-Linux.org> wrote this file. As long as you
* retain this notice you can do whatever you want with this stuff. If
* we meet some day, and you think this stuff is worth it, you can buy
* me a beer in return.
* ---------------------------------------------------------------------
* ______ _______ _ _________
* ( __ \ ( ___ )( ( /|( )\__ __/
* | ( \ )| ( ) || \ ( ||/ ) (
* | | ) || | | || \ | | | |
* | | | || | | || (\ \) | | |
* | | ) || | | || | \ | | |
* | (__/ )| (___) || ) \ | | |
* (______/ (_______)|/ )_) )_(
*
* _______ _______ _ _________ _______
* ( ____ )( ___ )( \ /|\__ __/( ____ \
* | ( )|| ( ) || \ ( | ) ( | ( |/
* | (____)|| (___) || \ | | | | | |
* | _____)| ___ || (\ \) | | | | |
* | ( | ( ) || | \ | | | | |
* | ) | ) ( || ) \ |___) (___| (____|\
* |/ |/ \||/ \_)\_______/(_______/
*
*/
#define _XOPEN_SOURCE
#include <ctype.h> // isprint
#include <errno.h> // errno
#include <stdint.h> // uint8_t
#include <libgen.h> // basename
#include <stdio.h> // fopen, fclose, fseek, ftell, fflush, fwrite
#include <stdlib.h> // exit, system
#include <string.h> // strcomp
#include <unistd.h> // getopt
static const char *__progname;
const int slice = 4096; // read/write 4k at a time
uint8_t Sflag; // sync
uint8_t uflag; // unlink
uint8_t vflag; // verbose
uint8_t wflag; // wipe
uint8_t zflag; // zero
uint8_t pass = 0;
uint8_t cpass = 1; // current pass
uint8_t tpass = 0;
static void usage() {
fprintf(stderr, "usage: %s [-hnSuvz] [FILE1]... [FILE2]...\n", __progname);
}
unsigned long int _findsize(char file[]) {
// opening the file in read mode
FILE *fp = fopen(file, "r");
// checking if the file exist or not
if (fp == NULL) {
perror("fopen");
exit(EXIT_FAILURE);
}
// seek to the file end
fseek(fp, 0L, SEEK_END);
// calculating the size of the file
unsigned long int fsize = ftell(fp);
// closing the file
fclose(fp);
return fsize;
}
void progress(int i) {
unsigned int c;
if (i < 10)
fprintf(stderr, " %i%% [", i);
else if (i < 100)
fprintf(stderr, " %i%% [", i);
else
fprintf(stderr, " %i%% [", i);
for (c = 0; c <= (i / 2); c++) {
fprintf(stderr, "#");
}
while (c <= 50) {
fprintf(stderr, "-");
c++;
}
fprintf(stderr, "]");
fprintf(stderr, "\r");
fflush(stderr);
}
int _shredit(char *file, char *dev, unsigned long int _size) {
char buf[slice]; // store our data in a buffer
FILE *dp; // the file stream for reading
unsigned long int done; // number of bytes written
uint8_t percent; // percentage finished
unsigned long int _tsize = (_size);
char *data; // data type
/* hide the cursor */
if (vflag)
system("tput civis");
/* Open the appropriate device file for reading */
if (strcmp(dev, "r") == 0) {
dp = fopen("/dev/urandom", "r");
data = "random";
} else if (strcmp(dev, "z") == 0) {
dp = fopen("/dev/zero", "r");
data = "000000";
} else {
// function called incorrectly (shutting up the compiler)
exit(1);
}
/* opening the device file failed */
if (dp == NULL) {
perror("fopen");
exit(EXIT_FAILURE);
}
/* Open our file for writing */
FILE *fp = fopen(file, "w");
/* opening the file failed */
if (fp == NULL) {
perror("fopen");
exit(EXIT_FAILURE);
}
while (_size > slice) {
if (fread(&buf, 1, slice, dp) != slice) {
perror("fread");
exit(EXIT_FAILURE);
}
if (fwrite(&buf, 1, slice, fp) != slice) {
perror("fwrite");
exit(EXIT_FAILURE);
}
if (vflag) {
done = _tsize - _size;
percent = done * 100 / _tsize;
fprintf(stderr, "%s: %s: pass %i/%i (%s)", __progname, file, cpass, tpass,
data);
progress(percent);
}
_size -= slice;
}
/* write the remaning bytes */
if (fread(&buf, 1, _size, dp) != _size) {
perror("fread");
exit(EXIT_FAILURE);
}
if (fwrite(&buf, 1, _size, fp) != _size) {
perror("fwrite");
exit(EXIT_FAILURE);
}
if (vflag) {
done = _tsize - slice;
fprintf(stderr, "%s: %s: pass %i/%i (%s)",
__progname, file, cpass, tpass, data);
progress(100);
fprintf(stderr, "\n");
}
/* flush and sync to disk */
if (Sflag) {
if (vflag)
fprintf(stderr, "Syncing to disk\n");
if (fflush(fp) != 0) {
perror("fflush");
exit(EXIT_FAILURE);
}
if (fsync(fileno(fp)) != 0) {
perror("fsync");
exit(EXIT_FAILURE);
}
}
/* Put our cursor back */
if (vflag)
system("tput cvvis");
// close streams
if (fclose(dp) != 0) {
perror("fclose");
exit(EXIT_FAILURE);
}
if (fclose(fp) != 0) {
perror("fclose");
exit(EXIT_FAILURE);
}
return 0;
}
int _unlinkit(char *file) {
if (unlink(file) == 0) {
if (vflag)
fprintf(stderr, "unlink: %s\n", file);
return 0;
} else {
perror("unlink");
exit(EXIT_FAILURE);
}
}
long parselong(char *buf) {
errno = 0;
char *endptr;
int num = strtol(optarg, &endptr, 10);
if (errno != 0) {
perror("Error parsing integer from input: ");
exit(EXIT_FAILURE);
} else if (num == 0 && endptr == optarg) {
fprintf(stderr, "Error: invalid input: %s\n", optarg);
exit(EXIT_FAILURE);
} else if (*endptr != '\0') {
fprintf(stderr, "Error: invalid input: %s\n", optarg);
exit(EXIT_FAILURE);
}
return num;
}
int main(int argc, char *argv[]) {
unsigned int index;
unsigned int c;
__progname = basename(argv[0]);
while ((c = getopt(argc, argv, "hSuvwzn:")) != -1)
switch (c) {
case 'h':
usage();
return 0;
break;
case 'n':
pass = parselong(optarg);
break;
case 'S':
Sflag = 1;
break;
case 'u':
uflag = 1;
break;
case 'v':
vflag = 1;
break;
case 'w':
wflag = 1;
break;
case 'z':
zflag = 1;
break;
case '?':
if (optopt == 'n')
fprintf(stderr, "Option -%c requires an argument.\n", optopt);
else if (isprint(optopt)) {
usage();
exit(1);
}
default:
usage();
}
// no arguments supplied
if (argv[optind] == NULL) {
fprintf(stderr, "Mandatory argument(s) missing\n");
exit(1);
}
for (index = optind; index < argc; index++) {
/* get the file size */
unsigned long int _size = _findsize(argv[index]);
/* number of passes */
if (pass == 0)
pass = 3;
cpass = 1; // reset current pass to 1 for each file
if (zflag)
tpass = (pass + 1); // zero adds an extra pass to total
else
tpass = (pass);
while (cpass <= pass) {
_shredit(argv[index], "r", _size);
cpass++;
}
/* final pass with zeros to cover our tracks somewhat */
if (zflag) {
_shredit(argv[index], "z", _size);
}
/* remove the file */
_unlinkit(argv[index]);
}
}