--- /dev/null
+/* A very simple, lite, version of tar for the Fuzix project
+
+ Copyright(c) 2015 Brett M Gordon
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+ NOTES:
+ * no record blocking
+ * cannot extract symbolic links
+ * hardlinks are added as normal files
+ * no built-in tar file, if option "f" is not set then tar will use
+ stdin/stdout.
+
+ TODO:
+ * don't archive the archive file
+*/
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <getopt.h>
+#include <dirent.h>
+/* #include <time.h> */
+#include <errno.h>
+
+/* tar header format, with ustar extension */
+struct header{
+ char name[100];
+ char mode[8];
+ char uid[8];
+ char gid[8];
+ char size[12];
+ char mtime[12];
+ char cksum[8];
+ char type;
+ char lname[100];
+ char ustar[6];
+ char version[2];
+ char uname[32];
+ char gname[32];
+ char major[8];
+ char minor[8];
+ char prefix[155];
+ char pad[12];
+}h;
+
+
+uint8_t buffer[512]; /* buffer for data blocks */
+int infile; /* input file: a tar file */
+int outfile; /* output file: a tar file */
+int verbose; /* verbose flag */
+int uflag; /* ustar flag */
+char *ofile=NULL; /* pointer to archive name from cmd line */
+char key=0; /* key mode of command (t,x,c) */
+int noreplace=0; /* replace old files? */
+int cksum=1; /* don't worry about cksums */
+
+
+/* Return a number from an octal string */
+static uint32_t b8get ( char *ptr, unsigned int n ){
+ uint32_t ret=0;
+ while( *ptr && n ){
+ ret *= 8;
+ ret += (*ptr++)-'0';
+ n--;
+ }
+ return ret;
+}
+
+/* Put a number in octal to string */
+static void b8put( uint32_t x, char *ptr ){
+ int digit;
+
+ *--ptr=0;
+ while(x){
+ digit = x & 7;
+ x /= 8;
+ *--ptr ='0'+digit;
+ }
+}
+
+/* Print filename for error reporting */
+static void pname(){
+ fprintf(stderr,"%s ", h.name );
+ perror( "" );
+}
+
+
+/* Change owner/group of file to match tar file */
+static void my_chown(){
+ int x=chown( h.name, b8get( h.uid, 8 ),
+ b8get( h.gid, 8 )
+ );
+ if( x < 0 ) pname();
+}
+
+
+/* Change mod of file to match tar file */
+static void my_chmod(){
+ int x=chmod( h.name, b8get( h.mode, 8 ) );
+ if( x < 0 ) pname();
+}
+
+static void printusage(){
+ fprintf(stderr, "usage: tar [-ckxntv] [-f archive] [file]...\n" );
+ exit(1);
+}
+
+/* skip data blocks of regular type file */
+static void skip(){
+ uint32_t size=b8get( h.size, 12 ) ;
+ uint32_t count= size / 512 ;
+ uint16_t rem = size % 512 ;
+
+ if( h.type == 0 || h.type == '0' ){
+ if( rem ) count++;
+ off_t x=lseek( infile, count*512, SEEK_CUR );
+ if( x < 0 ){
+ pname();
+ exit(1);
+ }
+
+ }
+}
+
+/* Calculate sum of header */
+static uint32_t cksum_calc(){
+ uint32_t acc=0;
+ unsigned char *ptr=(unsigned char *)h.name;
+ while( ptr != (unsigned char *)h.cksum )
+ acc += *ptr++;
+ acc += 32 * 8;
+ ptr = &(h.type);
+ while( ptr != (unsigned char *)h.pad )
+ acc += *ptr++;
+ return acc;
+}
+
+
+/* Prints information in header to stdout (if applicable) */
+static void printheader(){
+ char pad[10];
+ int pindex=10;
+ unsigned int m;
+ int x;
+
+ pad[10]=0;
+
+ /* don't print if creating to stdout */
+ if( !ofile && key=='c' ) return;
+
+ /* print verbosely */
+ if( verbose && key=='t' ){
+ /* print type */
+ switch( h.type ){
+ case '0':
+ case 0:
+ printf("-");
+ break;
+ case '1':
+ printf("h");
+ break;
+ case '2':
+ printf("s");
+ break;
+ case '3':
+ printf("c");
+ break;
+ case '4':
+ printf("b");
+ break;
+ case '5':
+ printf("d");
+ break;
+ case '6':
+ printf("f");
+ break;
+ default:
+ printf("?");
+ break;
+ }
+ /* print mode */
+ m=b8get( h.mode, 8 );
+ for( x=0; x<3; x++ ){
+ if( m & 1 )
+ pad[--pindex]='x';
+ else
+ pad[--pindex]='-';
+ m = m / 2;
+ if( m & 1 )
+ pad[--pindex]='w';
+ else
+ pad[--pindex]='-';
+ m = m / 2;
+
+ if( m & 1 )
+ pad[--pindex]='r';
+ else
+ pad[--pindex]='-';
+ m = m / 2;
+ }
+ printf( &(pad[pindex] ) );
+ /* print uid gid */
+ printf( " %4ld %4ld", b8get( h.uid, 8 ),
+ b8get( h.gid, 8 ) );
+ /* print file size */
+ printf( " %8ld ", b8get( h.size, 12 ) );
+ /* print maj/min */
+
+ /* This make binary big... disabling */
+ /*
+ printf( " %2ld,%2ld", b8get( h.major, 8 ),
+ b8get( h.minor, 8 ) );
+ {
+ char *s;
+ time_t time=b8get( h.mtime, 12 );
+ s=&( ctime( &time )[4] );
+ s[16]=0;
+ printf( " %-12s", s );
+ }
+ */
+
+ }
+ if( key == 't' || verbose )
+ printf("%s\n", h.name );
+}
+
+
+/* process a file name
+ This is called recursively as new subdirs are found */
+static void storedir( char *name){
+ struct stat s;
+ int fd;
+ int ret;
+ DIR *dirstream;
+ struct dirent *dir;
+ char cname[100];
+ uint32_t count;
+ uint16_t rem;
+
+ /* stat file */
+ ret=stat( name, &s );
+ if( ret<0 ){
+ fprintf(stderr,"%s ", name );
+ perror("");
+ return;
+ }
+
+ if( S_ISREG (s.st_mode ) ){
+ count = s.st_size / 512 ;
+ rem = s.st_size % 512 ;
+ if( rem ) count++;
+ }
+
+ /* build a new header in mem */
+ bzero( h.name, sizeof( h ) );
+ memset( h.mode,'0', 57 );
+ memset( h.major,'0',16 );
+ strcpy( h.name, name );
+ b8put( s.st_mode, h.mode + 8 );
+ b8put( s.st_uid, h.uid + 8 );
+ b8put( s.st_gid, h.gid + 8 );
+ b8put( s.st_size, h.size + 12 );
+ b8put( s.st_mtime, h.mtime + 12 );
+ switch( s.st_mode & S_IFMT ){
+ case S_IFREG:
+ h.type='0';
+ break;
+ case S_IFDIR:
+ h.type='5';
+ if( S_ISDIR( s.st_mode ) ) h.name[strlen(name)]='/';
+ break;
+ case S_IFCHR:
+ h.type='3';
+ b8put( s.st_rdev >> 8, h.major + 8 );
+ b8put( s.st_rdev & 255, h.minor + 8 );
+ break;
+ case S_IFBLK:
+ h.type='4';
+ b8put( s.st_rdev >> 8, h.major + 8 );
+ b8put( s.st_rdev & 255, h.minor + 8 );
+ break;
+ case S_IFIFO:
+ h.type='6';
+ break;
+ defailt:
+ fprintf(stderr,"unhandled file type error\n");
+ exit(1);
+ }
+
+ strcpy( h.ustar, "ustar" );
+ b8put( 0, h.version + 2 );
+
+ /* calculate checksum */
+ h.cksum[7]=32;
+ b8put( cksum_calc(), h.cksum + 7 );
+
+ /* write header to file */
+ ret = write( outfile, h.name, 512 );
+ if( ret < 512 ){
+ pname();
+ exit(1);
+ }
+ printheader();
+
+ switch( s.st_mode & S_IFMT ){
+ case S_IFREG:
+ /* open subject file */
+ fd=open( name, O_RDONLY );
+ if( fd<0 ){
+ fprintf(stderr, "%s ", name );
+ perror("");
+ return ;
+ }
+ while( count-- ){
+ ret = read( fd, buffer, 512 );
+ if( ret < 0 ){
+ fprintf(stderr,"cannot read source file\n");
+ exit(1);
+ }
+ /* !!! should zero rest of buffer here */
+ ret = write( outfile, buffer, 512 );
+ if( ret < 512 ){
+ fprintf(stderr,"cannot write out file\n");
+ exit(1);
+ }
+ }
+ close(fd);
+ break;
+ case S_IFDIR:
+ /* open the directory */
+ dirstream = opendir( name );
+ if( ret < 0 ){
+ pname();
+ break;
+ }
+ while( dir = readdir( dirstream ) ){
+ /* dont arch .. or . */
+ if( !strcmp( dir->d_name, "." ) ||
+ !strcmp( dir->d_name, ".." )
+ ) continue;
+ strncpy( cname, name, 100 );
+ strncat( cname, "/", 100 );
+ strncat( cname, dir->d_name, 100 );
+ {
+ /* save state of files */
+ uint32_t tell=telldir( dirstream );
+ closedir( dirstream );
+ /* recursive call to this dir */
+ storedir( cname );
+ /* restore state of files */
+ dirstream=opendir( name );
+ seekdir( dirstream, tell );
+ }
+ }
+ closedir( dirstream );
+ break;
+ }
+}
+
+
+/* list all the files in an archive */
+static void list( ){
+ int x;
+ int zcount=2;
+
+
+ if( ofile ) infile=open( ofile, O_RDONLY );
+ else infile = 0;
+ if( infile < 0 ){
+ perror( "Cannot open archive");
+ exit(1);
+ }
+
+ while(1){
+ x=read( infile, &h, 512 );
+ if( x < 512 ){
+ fprintf(stderr, "Bad filesize\n" );
+ exit(1);
+ }
+
+
+ /* check for zero block */
+ if ( h.name[0]==0 ){
+ if( ! --zcount )
+ exit(0);
+ continue;
+ }
+
+ uflag = ! strncmp( h.ustar, "ustar", 5 );
+
+ printheader();
+
+ skip();
+ } /* block while */
+}
+
+
+/* Extract all file in archive */
+static void extract( char *argv[] ){
+ int x;
+ char *ptr;
+ int zcount=2;
+
+ if( ofile ) infile=open( ofile, O_RDONLY );
+ else infile= 0;
+
+ if( infile < 0 ){
+ fprintf(stderr, "cannot open infile\n" );
+ exit(1);
+ }
+
+ while(1){
+ x=read( infile, &h, 512 );
+ if( x < 512 ){
+ fprintf(stderr, "bad filesize\n" );
+ exit(1);
+ }
+
+ /* check for zero block */
+ if ( h.name[0]==0 ){
+ if( ! --zcount )
+ exit(0);
+ continue;
+ }
+
+ /* check cksum */
+ if( cksum && (cksum_calc() != b8get( h.cksum, 8 )) ){
+ fprintf(stderr,"%s: bad chksum\n", h.name );
+ exit(1);
+ }
+
+ /* remove trailing '/' */
+ while( h.name[strlen(h.name)-1] == '/' )
+ h.name[strlen(h.name)-1] = 0;
+
+ /* does entry match any cmd line args? */
+ if( argv[optind] ){
+ for( x=optind; argv[x]; x++ ){
+ if( ! strcmp( h.name, argv[x] ) )
+ goto cont;
+ }
+ skip();
+ continue;
+ }
+ cont:
+ printheader();
+
+ uflag = ! strncmp( h.ustar, "ustar", 5 );
+
+ switch( h.type ){
+ case '1': /* a hard link */
+ x=link( h.lname, h.name );
+ if( x < 0 ){
+ pname();
+ break;
+ }
+ my_chmod();
+ my_chown();
+ break;
+ case '2': /* a soft link */
+ fprintf(stderr, "soft links not supported\n" );
+ break;
+ case '3': /* a charactor device */
+ x=mknod( h.name, b8get( h.mode, 8 )|S_IFCHR,
+ (b8get(h.major,8)<<8)+b8get(h.minor,8) );
+ if( x > 0 ){
+ pname();
+ break;
+ }
+ my_chown();
+ break;
+ case '4': /* a block device */
+ x=mknod( h.name, b8get( h.mode, 8)|S_IFBLK,
+ (b8get(h.major,8)<<8)+b8get(h.minor,8));
+ if( x < 0 ){
+ pname();
+ break;
+ }
+ my_chown();
+ break;
+ case '5': /* a directory */
+ x=mkdir( h.name, b8get( h.mode, 8 ) );
+ if( x ){
+ pname();
+ break;
+ }
+ my_chown();
+ break;
+ case '6': /* a FIFO */
+ x=mkfifo( h.name, b8get( h.mode, 8) );
+ if( x < 0 ){
+ pname();
+ break;
+ }
+ my_chown();
+ break;
+ case '0': /* regular file */
+ case 0:
+ {
+ int i;
+ /* get a printable size */
+ uint32_t size=b8get( h.size, 12 ) ;
+ uint32_t count;
+ /* count how many blocks we need */
+ count = size / 512 ;
+ uint16_t rem = size % 512 ;
+ /* check for existance of file */
+ if( noreplace && !access( h.name, F_OK ) ){
+ errno=EEXIST;
+ pname();
+ continue;
+ }
+ /* open output file */
+ outfile=open(h.name,O_CREAT|O_WRONLY);
+ if( outfile < 0 ){
+ pname();
+ break;
+ }
+ /* send buffers to file */
+ for( x=0; x<count; x++){
+ i = read( infile, buffer, 512 );
+ if( i < 512 ){
+ fprintf(stderr,"cannot read source file\n");
+ exit(1);
+ }
+ i = write( outfile, buffer, 512 );
+ if( i < 512 ){
+ fprintf(stderr,"cannot write out file\n");
+ exit(1);
+ }
+ }
+ if( rem ){
+ i = read( infile, buffer, 512 );
+ if( i < 512 ){
+ fprintf(stderr,"cannot read source file\n");
+ exit(1);
+ }
+ i = write( outfile, buffer, rem );
+ if( i < rem ){
+ fprintf(stderr,"cannot write out file\n");
+ exit(1);
+ }
+ }
+ close( outfile );
+ my_chmod();
+ my_chown();
+ continue;
+ }
+ break;
+ default:
+ fprintf(stderr,"unsupported flag\n");
+ break;
+ }
+ } /* block while */
+}
+
+
+/* Create a archive */
+static void create( char *argv[] ){
+ int x;
+ /* open outfile */
+ if( ofile ) outfile=open( ofile, O_CREAT|O_WRONLY, 0666 );
+ else outfile=1;
+ if( outfile < 0 ){
+ pname();
+ exit(1);
+ }
+ /* put each file on cmdline to file */
+ while( argv[optind] ){
+ char *s = argv[optind++];
+ /* remove any trailing / */
+ if( s[strlen(s)-1] == '/' ) s[strlen(s)-1]=0;
+ /* remove any leading / */
+ if( s[0] == '/' ) s=s+1;
+ storedir( s );
+ }
+ /* write out 2 zero blocks */
+ bzero( buffer, 512 );
+ x = write( outfile, buffer, 512 );
+ x += write( outfile, buffer, 512 );
+ if( x != 1024 )
+ perror("writing end of archive");
+ /* close outfile */
+ close(outfile);
+ exit(0);
+}
+
+
+int main( int argc, char *argv[] ){
+ int o;
+
+ while( (o= getopt( argc, argv,"xtcvnkf:"))>0 ){
+ switch( o ){
+ case 'x':
+ case 't':
+ case 'c':
+ key=o;
+ break;
+ case 'v':
+ verbose=1;
+ break;
+ case 'f':
+ ofile=optarg;
+ break;
+ case 'k':
+ noreplace=1;
+ break;
+ case 'n':
+ cksum=0;
+ break;
+ default:
+ printusage();
+ }
+ }
+
+ switch( key ){
+ case 'x':
+ extract( argv );
+ case 't':
+ list( );
+ case 'c':
+ create( argv );
+ default:
+ fprintf(stderr, "tar: option x,c, or t must be used\n" );
+ }
+
+}
+
+
+
+
public / FUZIX.git / commitdiff