sltar

commit b28e88a9158caca85042a9f49953c334e2343da4
parent 0c3b317cab86de9a9ac645d4155c7238956bfd0c
Author: gottox@rootkit.lan <unknown>
Date:   Wed, 19 Dec 2007 10:12:10 +0100

Seems to extract now properly; renaming tar to sltar
Diffstat:
Makefile
 | 
6
+++---
config.mk
 | 
2
+-
tar.c
 | 
97
+++++++++++++++++++++++++++++++++++++++++++++++--------------------------------

3 files changed, 62 insertions(+), 43 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,11 +1,11 @@
-# tar - a minimal implementation of tar
+# sltar - a minimal implementation of tar
 # (c) 2007 Enno Boland
 
 include config.mk
 
-SRC = tar.c
+SRC = sltar.c
 OBJ = ${SRC:.c=.o}
-TARGET = tar
+TARGET = sltar
 
 all: options ${TARGET}
 
diff --git a/config.mk b/config.mk
@@ -1,4 +1,4 @@
-# tar version
+# sltar version
 VERSION = 0.0
 
 # Customize below to fit your system
diff --git a/tar.c b/tar.c
@@ -1,57 +1,76 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #define USAGE { puts("tar [xt]"); exit(EXIT_FAILURE); }
-#define FORBLOCK(x,b) for(l = x; l > 0 && (n = read(0,(void *)(b),512)) > 0; l -= n)
 
-/* POSIX tar Header Block, from POSIX 1003.1-1990  */
-struct Header
-{
-	/* Header: 512 Byte */
-	char name[100];		/* 0-99 */
-	char mode[8];		/* 100-107 */
-	char uid[8];		/* 108-115 */
-	char gid[8];		/* 116-123 */
-	char size[12];		/* 124-135 */
-	char mtime[12];		/* 136-147 */
-	char chksum[8];		/* 148-155 */
-	char typeflag;		/* 156-156 */
-	char linkname[100];	/* 157-256 */
-	char magic[6];		/* 257-262 */
-	char version[2];	/* 263-264 */
-	char uname[32];		/* 265-296 */
-	char gname[32];		/* 297-328 */
-	char devmajor[8];	/* 329-336 */
-	char devminor[8];	/* 337-344 */
-	char prefix[155];	/* 345-499 */
-	char padding[12];	/* 500-512 */
+enum Header {
+	MODE = 100, UID = 108, GID = 116, SIZE = 124, MTIME = 136,
+	TYPE = 156, LINK = 157, DEVMAJOR = 329, DEVMINOR = 337,
+	END = 512
 };
 
 int main(int argc, char *argv[]) {
-	int a, l, n;
-	char b[512];
-	struct Header h;
+	int a, l;
+	char b[END],fname[101],lname[101];
+	FILE *f;
 
 	if((argc != 2 || (a = argv[1][0]) == '\0') ||
 			argv[1][1] != '\0' || (a != 't' && a != 'x'))
 		USAGE;
-	while(1) {
-		FORBLOCK(sizeof(h),&h);
-		if(*h.name == '\0')
-			break;
-		else if(l != 0) {
-			fputs("Garbage!\n",stderr);
-			return EXIT_FAILURE;
+	lname[100] = fname[100] = '\0';
+	for(l = 0, f = NULL; fread(b,END,1,stdin); l -= END) {
+		if(l <= 0) {
+			if(*b == '\0')
+				break;
+			memcpy(fname,b,100);
+			memcpy(lname,b+LINK,100);
+			switch(a) {
+			case 't':
+				puts(fname);
+				break;
+			case 'x':
+				if(f) {
+					fclose(f);
+					f = NULL;
+				}
+				unlink(b);
+				switch(b[TYPE]) {
+				case '0': /* file */
+					if(!(f = fopen(b,"w")))
+						perror(fname);
+					break;
+				case '1': /* hardlink */
+					if(!link(lname,fname))
+						perror(fname);
+					break;
+				case '2': /* symlink */
+					if(!symlink(lname,fname))
+						perror(fname);
+					break;
+				case '5': /* directory */
+					if(mkdir(fname,(mode_t) strtoull(b+MODE,0,8)))
+						perror(fname);
+					break;
+				case '4': /* block device */
+				case '3': /* char device */
+					break;
+				case '6': /* fifo */
+					break;
+				default:
+					fprintf(stderr,"%s: type `%c` is not supported",fname,b[TYPE]);
+				}
+			}
+			l = strtoull(b+SIZE,0,8)+END;
 		}
-		if(a == 't') {
-			puts(h.name);
-			FORBLOCK(strtoull(h.size,0,8),b);
-		}
-		else {
-			FORBLOCK(strtoull(h.size,0,8),b)
-				puts("open, write, close, chmod, chown");
+		else if(a == 'x' && f) {
+			
 		}
 	}
+	if(f)
+		fclose(f);
 	return EXIT_SUCCESS;
 }