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-rw-r--r--src/util/dir_forest.c110
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diff --git a/src/util/dir_forest.c b/src/util/dir_forest.c
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+/*++
+/* NAME
+/* dir_forest 3
+/* SUMMARY
+/* file name to directory forest
+/* SYNOPSIS
+/* #include <dir_forest.h>
+/*
+/* char *dir_forest(buf, path, depth)
+/* VSTRING *buf;
+/* const char *path;
+/* int depth;
+/* DESCRIPTION
+/* This module implements support for directory forests: a file
+/* organization that introduces one or more levels of intermediate
+/* subdirectories in order to reduce the number of files per directory.
+/*
+/* dir_forest() maps a file basename to a directory forest and
+/* returns the resulting string: file name "abcd" becomes "a/b/"
+/* and so on. The number of subdirectory levels is adjustable.
+/*
+/* Arguments:
+/* .IP buf
+/* A buffer that is overwritten with the result. The result
+/* ends in "/" and is null terminated. If a null pointer is
+/* specified, the result is written to a private buffer that
+/* is overwritten upon each call.
+/* .IP path
+/* A null-terminated string of printable characters. Characters
+/* special to the file system are not permitted.
+/* The first subdirectory is named after the first character
+/* in \fIpath\fR, and so on. When the path is shorter than the
+/* desired number of subdirectory levels, directory names
+/* of '_' (underscore) are used as replacement.
+/* .IP depth
+/* The desired number of subdirectory levels.
+/* DIAGNOSTICS
+/* Panic: interface violations. Fatal error: out of memory.
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <ctype.h>
+
+/* Utility library. */
+
+#include "msg.h"
+#include "dir_forest.h"
+
+/* dir_forest - translate base name to directory forest */
+
+char *dir_forest(VSTRING *buf, const char *path, int depth)
+{
+ const char *myname = "dir_forest";
+ static VSTRING *private_buf = 0;
+ int n;
+ const char *cp;
+ int ch;
+
+ /*
+ * Sanity checks.
+ */
+ if (*path == 0)
+ msg_panic("%s: empty path", myname);
+ if (depth < 1)
+ msg_panic("%s: depth %d", myname, depth);
+
+ /*
+ * Your buffer or mine?
+ */
+ if (buf == 0) {
+ if (private_buf == 0)
+ private_buf = vstring_alloc(1);
+ buf = private_buf;
+ }
+
+ /*
+ * Generate one or more subdirectory levels, depending on the pathname
+ * contents. When the pathname is short, use underscores instead.
+ * Disallow non-printable characters or characters that are special to
+ * the file system.
+ */
+ VSTRING_RESET(buf);
+ for (cp = path, n = 0; n < depth; n++) {
+ if ((ch = *cp) == 0) {
+ ch = '_';
+ } else {
+ if (!ISPRINT(ch) || ch == '.' || ch == '/')
+ msg_panic("%s: invalid pathname: %s", myname, path);
+ cp++;
+ }
+ VSTRING_ADDCH(buf, ch);
+ VSTRING_ADDCH(buf, '/');
+ }
+ VSTRING_TERMINATE(buf);
+
+ if (msg_verbose > 1)
+ msg_info("%s: %s -> %s", myname, path, vstring_str(buf));
+ return (vstring_str(buf));
+}