blkpack and blkunpack tools from collapseos

tools/blkpack.c

@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+
+static int lineno;
+
+static void emptylines(int n)
+{
+  for (int i=0; i<64*n; i++) putchar(0x20);
+}
+
+static int getmarker(char *line) // returns -1 on error, blkid otherwise
+{
+    int blkid;
+    int r = sscanf(line, "( ----- %d )\n", &blkid);
+    if (r == 1) {
+        return blkid;
+    } else {
+        return -1;
+    }
+}
+
+static int expectmarker(char *line)
+{
+    int blkid = getmarker(line);
+    if (blkid < 0) { // could not scan
+        fprintf(
+            stderr, "Error at line %d: expecting block marker\n", lineno);
+    }
+    return blkid;
+}
+
+static void usage()
+{
+    fprintf(stderr, "Usage: blkpack < blk.fs > blkfs\n");
+}
+
+int main(int argc, char *argv[])
+{
+    int prevblkid = -1;
+    int blkid;
+    char *line = NULL;
+    if (argc != 1) {
+        usage();
+        return 1;
+    }
+    lineno = 1;
+    size_t n = 0;
+    ssize_t cnt = getline(&line, &n, stdin);
+    if (cnt <= 0) {
+        fprintf(stderr, "No input\n");
+        return 1;
+    }
+    while (1) {
+        blkid = expectmarker(line);
+        if (blkid < 0) return 1;
+        if (blkid <= prevblkid) {
+            fprintf(
+                stderr,
+                "Wrong blkid (%d) at line %d: blocks must be ordered\n",
+                blkid, lineno);
+            return 1;
+        }
+        emptylines((blkid-prevblkid-1)*16);
+        int blkline;
+        for (blkline=0; blkline<16; blkline++) {
+            lineno++;
+            cnt = getline(&line, &n, stdin);
+            if (cnt <= 0) break; // EOF
+            if (cnt > 65) {
+                fprintf(stderr, "Line %d too long (blk %d)\n", lineno, blkid);
+                return 1;
+            }
+            if (getmarker(line) >= 0) break; // we have a marker early
+            line[cnt-1] = '\0'; // remove newline
+            printf("%s", line);
+            // pad line to 64 chars
+            for (int i=cnt-1; i<64; i++) putchar(0x20);
+        }
+        if (blkline == 16) {
+            lineno++;
+            cnt = getline(&line, &n, stdin);
+        } else {
+            // fill to 16 lines
+            emptylines(16-blkline);
+        }
+        if (cnt <= 0) break; // EOF
+        prevblkid = blkid;
+    }
+    free(line);
+    return 0;
+}
+

tools/blkunpack.c

@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+/* Unpacks blkfs into its source form.
+ *
+ * If numerical "startat" is specified, blkno start at this number.
+ *
+ * Whitespaces at the right of every line are trimmed.
+ */
+void usage()
+{
+    fprintf(stderr, "Usage: blkunpack [startat] < blkfs > blk.fs\n");
+}
+
+int main(int argc, char *argv[])
+{
+    char buf[1024];
+    int blkid = 0;
+    if (argc > 2) {
+        usage();
+        return 1;
+    }
+    if (argc == 2) {
+        blkid = strtol(argv[1], NULL, 10);
+    }
+    while (fread(buf, 1024, 1, stdin) == 1) {
+        int linecnt = 0 ;
+        for (int i=1023; i>=0; i--) {
+            if (buf[i] > ' ') {
+                linecnt = (i / 64) + 1;
+                break;
+            }
+        }
+        if (linecnt) {
+            // not an empty block
+            printf("( ----- %03d )\n", blkid);
+            for (int i=0; i<linecnt; i++) {
+                char *line = &buf[i*64];
+                // line length is *not* strlen()! it's the position of the
+                // first non-WS, starting from the right. Then, we normalize
+                // nulls to space.
+                int j;
+                for (j=63; j>=0; j--) {
+                    if (line[j] > ' ') {
+                        break;
+                    }
+                }
+                int len = j+1;
+                if (len) {
+                    for (; j>=0; j--) {
+                        if (line[j] == '\0') {
+                            line[j] = ' ';
+                        }
+                    }
+                    fwrite(line, len, 1, stdout);
+                }
+                fputc('\n', stdout);
+            }
+        }
+        blkid++;
+    }
+    return 0;
+}