Add -N, -I, -L, and -P options to cksum.

diff --git a/lib/bunzip.c b/lib/bunzip.c
index 18984af..f860aa6 100644 (file)
--- a/lib/bunzip.c
+++ b/lib/bunzip.c
@@ -609,7 +609,7 @@ int start_bunzip(struct bunzip_data **bdp, int src_fd, char *inbuf, int len)
                bd->in_fd = src_fd;
        }
 
-       crc_init(bd->crc32Table);
+       crc_init(bd->crc32Table, 0);
 
        // Ensure that file starts with "BZh".
     for (i=0;i<3;i++)

diff --git a/lib/lib.c b/lib/lib.c
index f94d6fd..89c8781 100644 (file)
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -721,15 +721,16 @@ void replace_tempfile(int fdin, int fdout, char **tempname)
 
 // Create a 256 entry CRC32 lookup table.
 
-void crc_init(unsigned int *crc_table)
+void crc_init(unsigned int *crc_table, int little_endian)
 {
        unsigned int i;
 
        // Init the CRC32 table (big endian)
        for (i=0; i<256; i++) {
-               unsigned int j, c = i<<24;
+               unsigned int j, c = little_endian ? i : i<<24;
                for (j=8; j; j--)
-                       c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1);
+                       if (little_endian) c = (c&1) ? (c>>1)^0xEDB88320 : c>>1;
+                       else c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1);
                crc_table[i] = c;
        }
 }

diff --git a/lib/lib.h b/lib/lib.h
index 2fcdaa4..a473b54 100644 (file)
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -96,7 +96,7 @@ void xsendfile(int in, int out);
 int copy_tempfile(int fdin, char *name, char **tempname);
 void delete_tempfile(int fdin, int fdout, char **tempname);
 void replace_tempfile(int fdin, int fdout, char **tempname);
-void crc_init(unsigned int *crc_table);
+void crc_init(unsigned int *crc_table, int little_endian);
 
 // getmountlist.c
 struct mtab_list {

diff --git a/toys/cksum.c b/toys/cksum.c
index a54738c..9b61667 100644 (file)
--- a/toys/cksum.c
+++ b/toys/cksum.c
@@ -6,18 +6,21 @@
  *
  * See http://www.opengroup.org/onlinepubs/009695399/utilities/cksum.html
 
-USE_CKSUM(NEWTOY(cksum, "F", TOYFLAG_BIN))
+USE_CKSUM(NEWTOY(cksum, "IPLN", TOYFLAG_BIN))
 
 config CKSUM
        bool "cksum"
        default y
        help
-         usage: cksum [-F] [file...]
+         usage: cksum [-FL] [file...]
 
          For each file, output crc32 checksum value, length and name of file.
          If no files listed, copy from stdin.  Filename "-" is a synonym for stdin.
 
-         -F    Start with 0xffffffff instead of 0.
+         -L    Little endian (defaults to big endian)
+         -P    Skip pre-inversion
+         -I    Skip post-inversion
+         -N    No length
 */
 
 #include "toys.h"
@@ -28,16 +31,24 @@ DEFINE_GLOBALS(
 
 #define TT this.cksum
 
-static unsigned cksum(unsigned crc, unsigned char c)
+static unsigned cksum_be(unsigned crc, unsigned char c)
 {
        return (crc<<8)^TT.crc_table[(crc>>24)^c];
 }
 
+static unsigned cksum_le(unsigned crc, unsigned char c)
+{
+       return TT.crc_table[(crc^c)&0xff] ^ (crc>>8);
+}
+
 static void do_cksum(int fd, char *name)
 {
-       unsigned crc = toys.optflags ? 0xffffffff : 0;
+       unsigned crc = (toys.optflags&4) ? 0 : 0xffffffff;
        uint64_t llen = 0, llen2;
+       unsigned (*cksum)(unsigned crc, unsigned char c);
 
+
+       cksum = (toys.optflags&2) ? cksum_le : cksum_be;
        // CRC the data
 
        for (;;) {
@@ -57,18 +68,20 @@ static void do_cksum(int fd, char *name)
        // CRC the length
 
        llen2 = llen;
-       while (llen) {
-               crc = cksum(crc, llen);
-               llen >>= 8;
+       if (!(toys.optflags&1)) {
+               while (llen) {
+                       crc = cksum(crc, llen);
+                       llen >>= 8;
+               }
        }
 
-       printf("%u %"PRIu64, ~crc, llen2);
+       printf("%u %"PRIu64, (toys.optflags&8) ? crc : ~crc, llen2);
        if (strcmp("-", name)) printf(" %s", name);
        xputc('\n');
 }
 
 void cksum_main(void)
 {
-       crc_init(TT.crc_table);
+       crc_init(TT.crc_table, toys.optflags&2);
        loopfiles(toys.optargs, do_cksum);
 }