Fix/update (de)compress utils

bin/src/compress.c

@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <sys/stat.h>
 
 const int MAXLENGTH = 0x300;
@@ -7,11 +8,11 @@ const int MAXLENGTH = 0x300;
 struct section {
     int mode;
     int length;
-    char data[2];
+    unsigned char data[2];
     int datalength;
 };
 
-int find_duplicate(off_t loc, off_t size, char buf[], struct section *out) {
+int find_duplicate(off_t loc, off_t size, unsigned char buf[], struct section *out) {
     int i, j;
     struct section result;
     result.mode = 4;
@@ -39,7 +40,7 @@ int find_duplicate(off_t loc, off_t size, char buf[], struct section *out) {
     return 0;
 }
 
-int find_repeat_byte(off_t loc, off_t size, char buf[], struct section *out) {
+int find_repeat_byte(off_t loc, off_t size, unsigned char buf[], struct section *out) {
     int i;
     for (i = 0; i < MAXLENGTH && loc + i < size; i++) {
         if (buf[loc + i] != buf[loc]) {
@@ -58,7 +59,7 @@ int find_repeat_byte(off_t loc, off_t size, char buf[], struct section *out) {
     return -1;
 }
 
-int find_repeat_word(off_t loc, off_t size, char buf[], struct section *out) {
+int find_repeat_word(off_t loc, off_t size, unsigned char buf[], struct section *out) {
     int i;
     for (i = 0; i < MAXLENGTH && loc + i + 1 < size; i += 1) {
         if (buf[loc + i] != buf[loc + (i & 1)]) {
@@ -78,7 +79,7 @@ int find_repeat_word(off_t loc, off_t size, char buf[], struct section *out) {
     return -1;
 }
 
-int find_incrementing_byte(off_t loc, off_t size, char buf[], struct section *out) {
+int find_incrementing_byte(off_t loc, off_t size, unsigned char buf[], struct section *out) {
     int i;
     for (i = 0; i < MAXLENGTH && loc + i < size; i++) {
         if (buf[loc] + i < i) {
@@ -100,7 +101,7 @@ int find_incrementing_byte(off_t loc, off_t size, char buf[], struct section *ou
     return -1;
 }
 
-int get_section(off_t loc, off_t size, char buf[], struct section *out) {
+int get_section(off_t loc, off_t size, unsigned char buf[], struct section *out) {
     struct section best, current;
     best.length = 0;
     if (!find_repeat_byte(loc, size, buf, &current)) {
@@ -132,7 +133,7 @@ int get_section(off_t loc, off_t size, char buf[], struct section *out) {
     }
 }
 
-int write_section(struct section section, char data[], char buf[], int loc) {
+int write_section(struct section section, unsigned char data[], unsigned char buf[], int loc) {
     int nloc = loc;
     int len = section.length - 1;
     if (len > 0x1F) {
@@ -149,10 +150,15 @@ int write_section(struct section section, char data[], char buf[], int loc) {
 
 int main(int argc, char *argv[]) {
     if (argc < 3) {
-        printf("Usage: %s infile outfile\n", argv[0]);
+        printf("Usage: %s infile outfile [start [length]]\n", argv[0]);
         return 1;
     }
 
+    off_t seek = 0;
+    if (argc > 3) {
+        seek = strtol(argv[3], NULL, 0);
+    }
+
     FILE *inptr;
     if ((inptr = fopen(argv[1], "rb")) == NULL) {
         printf("%s does not exist.\n", argv[1]);
@@ -170,9 +176,14 @@ int main(int argc, char *argv[]) {
         printf("Error stating file: %s\n", argv[1]);
         return 1;
     }
-    off_t size = buf.st_size;
+    off_t size = buf.st_size - seek;
 
-    char inbuf[size];
+    if (argc > 4) {
+        size = strtol(argv[4], NULL, 0);
+    }
+    unsigned char inbuf[size];
+
+    fseek(inptr, seek, SEEK_SET);
 
     if (fread(inbuf, 1, size, inptr) < size) {
         printf("Error reading file: %s\n", argv[1]);
@@ -181,9 +192,8 @@ int main(int argc, char *argv[]) {
 
     fclose(inptr);
 
-
-    char outbuf[size * 2];
-    char m0data[MAXLENGTH];
+    unsigned char outbuf[size * 2];
+    unsigned char m0data[MAXLENGTH];
 
     int oloc = 0;
     struct section m0;
@@ -233,7 +243,7 @@ int main(int argc, char *argv[]) {
     }
 
     fclose(outptr);
-    printf("Input file: %X bytes. Compressed: %X bytes.\n", size, oloc);
+    printf("Input file: %lX bytes. Compressed: %X bytes.\n", size, oloc);
 
     return 0;
 }

bin/src/decompress.c

@@ -1,21 +1,20 @@
 #include <stdio.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <sys/stat.h>
 
 struct section {
     int mode;
     int length;
-    char data[2];
+    unsigned char data[2];
     int datalength;
 };
 
-int read_section(char buf[], int loc, struct section *out) {
+int read_section(unsigned char buf[], int loc, struct section *out) {
     int nloc = loc;
-    char header = buf[nloc++];
+    unsigned char header = buf[nloc++];
 
-    printf("%x: ", header & 0xff);
-
-    if (header == -1) {
+    if (header == 0xFF) {
       return -1;
     }
 
@@ -31,8 +30,6 @@ int read_section(char buf[], int loc, struct section *out) {
       result.length = (header & 0x1F) + 1;
     }
 
-    printf("%d: %x\n", result.mode, result.length);
-
     switch (result.mode) {
       case 0:
         result.datalength = 0;
@@ -61,10 +58,15 @@ int read_section(char buf[], int loc, struct section *out) {
 
 int main(int argc, char *argv[]) {
     if (argc < 3) {
-        printf("Usage: %s infile outfile\n", argv[0]);
+        printf("Usage: %s infile outfile [start [length]]\n", argv[0]);
         return 1;
     }
 
+    off_t seek = 0;
+    if (argc > 3) {
+        seek = strtol(argv[3], NULL, 0);
+    }
+
     FILE *inptr;
     if ((inptr = fopen(argv[1], "rb")) == NULL) {
         printf("%s does not exist.\n", argv[1]);
@@ -82,9 +84,15 @@ int main(int argc, char *argv[]) {
         printf("Error stating file: %s\n", argv[1]);
         return 1;
     }
-    off_t size = buf.st_size;
 
-    char inbuf[size];
+    off_t size = buf.st_size - seek;
+
+    if (argc > 4) {
+        size = strtol(argv[4], NULL, 0);
+    }
+
+    fseek(inptr, seek, SEEK_SET);
+    unsigned char inbuf[size];
 
     if (fread(inbuf, 1, size, inptr) < size) {
         printf("Error reading file: %s\n", argv[1]);
@@ -93,7 +101,7 @@ int main(int argc, char *argv[]) {
 
     fclose(inptr);
 
-    char outbuf[size * 256];
+    unsigned char outbuf[size * 256];
 
     int oloc = 0;
     struct section section;
@@ -141,7 +149,7 @@ int main(int argc, char *argv[]) {
     }
 
     fclose(outptr);
-    printf("Input file: %X bytes. Decompressed: %X bytes.\n", size, oloc);
+    printf("Input file: %lX bytes. Decompressed: %X bytes.\n", size, oloc);
 
     return 0;
 }