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-rw-r--r--abspath.c238
1 files changed, 166 insertions, 72 deletions
diff --git a/abspath.c b/abspath.c
index 2825de8591..b02e068aa3 100644
--- a/abspath.c
+++ b/abspath.c
@@ -11,46 +11,83 @@ int is_directory(const char *path)
return (!stat(path, &st) && S_ISDIR(st.st_mode));
}
+/* removes the last path component from 'path' except if 'path' is root */
+static void strip_last_component(struct strbuf *path)
+{
+ size_t offset = offset_1st_component(path->buf);
+ size_t len = path->len;
+
+ /* Find start of the last component */
+ while (offset < len && !is_dir_sep(path->buf[len - 1]))
+ len--;
+ /* Skip sequences of multiple path-separators */
+ while (offset < len && is_dir_sep(path->buf[len - 1]))
+ len--;
+
+ strbuf_setlen(path, len);
+}
+
+/* get (and remove) the next component in 'remaining' and place it in 'next' */
+static void get_next_component(struct strbuf *next, struct strbuf *remaining)
+{
+ char *start = NULL;
+ char *end = NULL;
+
+ strbuf_reset(next);
+
+ /* look for the next component */
+ /* Skip sequences of multiple path-separators */
+ for (start = remaining->buf; is_dir_sep(*start); start++)
+ ; /* nothing */
+ /* Find end of the path component */
+ for (end = start; *end && !is_dir_sep(*end); end++)
+ ; /* nothing */
+
+ strbuf_add(next, start, end - start);
+ /* remove the component from 'remaining' */
+ strbuf_remove(remaining, 0, end - remaining->buf);
+}
+
+/* copies root part from remaining to resolved, canonicalizing it on the way */
+static void get_root_part(struct strbuf *resolved, struct strbuf *remaining)
+{
+ int offset = offset_1st_component(remaining->buf);
+
+ strbuf_reset(resolved);
+ strbuf_add(resolved, remaining->buf, offset);
+#ifdef GIT_WINDOWS_NATIVE
+ convert_slashes(resolved->buf);
+#endif
+ strbuf_remove(remaining, 0, offset);
+}
+
/* We allow "recursive" symbolic links. Only within reason, though. */
-#define MAXDEPTH 5
+#ifndef MAXSYMLINKS
+#define MAXSYMLINKS 32
+#endif
/*
* Return the real path (i.e., absolute path, with symlinks resolved
* and extra slashes removed) equivalent to the specified path. (If
* you want an absolute path but don't mind links, use
- * absolute_path().) The return value is a pointer to a static
- * buffer.
+ * absolute_path().) Places the resolved realpath in the provided strbuf.
*
- * The input and all intermediate paths must be shorter than MAX_PATH.
* The directory part of path (i.e., everything up to the last
* dir_sep) must denote a valid, existing directory, but the last
* component need not exist. If die_on_error is set, then die with an
* informative error message if there is a problem. Otherwise, return
* NULL on errors (without generating any output).
- *
- * If path is our buffer, then return path, as it's already what the
- * user wants.
*/
-static const char *real_path_internal(const char *path, int die_on_error)
+char *strbuf_realpath(struct strbuf *resolved, const char *path,
+ int die_on_error)
{
- static struct strbuf sb = STRBUF_INIT;
+ struct strbuf remaining = STRBUF_INIT;
+ struct strbuf next = STRBUF_INIT;
+ struct strbuf symlink = STRBUF_INIT;
char *retval = NULL;
-
- /*
- * If we have to temporarily chdir(), store the original CWD
- * here so that we can chdir() back to it at the end of the
- * function:
- */
- struct strbuf cwd = STRBUF_INIT;
-
- int depth = MAXDEPTH;
- char *last_elem = NULL;
+ int num_symlinks = 0;
struct stat st;
- /* We've already done it */
- if (path == sb.buf)
- return path;
-
if (!*path) {
if (die_on_error)
die("The empty string is not a valid path");
@@ -58,86 +95,136 @@ static const char *real_path_internal(const char *path, int die_on_error)
goto error_out;
}
- strbuf_reset(&sb);
- strbuf_addstr(&sb, path);
-
- while (depth--) {
- if (!is_directory(sb.buf)) {
- char *last_slash = find_last_dir_sep(sb.buf);
- if (last_slash) {
- last_elem = xstrdup(last_slash + 1);
- strbuf_setlen(&sb, last_slash - sb.buf + 1);
- } else {
- last_elem = xmemdupz(sb.buf, sb.len);
- strbuf_reset(&sb);
- }
+ strbuf_addstr(&remaining, path);
+ get_root_part(resolved, &remaining);
+
+ if (!resolved->len) {
+ /* relative path; can use CWD as the initial resolved path */
+ if (strbuf_getcwd(resolved)) {
+ if (die_on_error)
+ die_errno("unable to get current working directory");
+ else
+ goto error_out;
}
+ }
- if (sb.len) {
- if (!cwd.len && strbuf_getcwd(&cwd)) {
+ /* Iterate over the remaining path components */
+ while (remaining.len > 0) {
+ get_next_component(&next, &remaining);
+
+ if (next.len == 0) {
+ continue; /* empty component */
+ } else if (next.len == 1 && !strcmp(next.buf, ".")) {
+ continue; /* '.' component */
+ } else if (next.len == 2 && !strcmp(next.buf, "..")) {
+ /* '..' component; strip the last path component */
+ strip_last_component(resolved);
+ continue;
+ }
+
+ /* append the next component and resolve resultant path */
+ if (!is_dir_sep(resolved->buf[resolved->len - 1]))
+ strbuf_addch(resolved, '/');
+ strbuf_addbuf(resolved, &next);
+
+ if (lstat(resolved->buf, &st)) {
+ /* error out unless this was the last component */
+ if (errno != ENOENT || remaining.len) {
if (die_on_error)
- die_errno("Could not get current working directory");
+ die_errno("Invalid path '%s'",
+ resolved->buf);
else
goto error_out;
}
+ } else if (S_ISLNK(st.st_mode)) {
+ ssize_t len;
+ strbuf_reset(&symlink);
+
+ if (num_symlinks++ > MAXSYMLINKS) {
+ errno = ELOOP;
- if (chdir(sb.buf)) {
if (die_on_error)
- die_errno("Could not switch to '%s'",
- sb.buf);
+ die("More than %d nested symlinks "
+ "on path '%s'", MAXSYMLINKS, path);
else
goto error_out;
}
- }
- if (strbuf_getcwd(&sb)) {
- if (die_on_error)
- die_errno("Could not get current working directory");
- else
- goto error_out;
- }
- if (last_elem) {
- if (sb.len && !is_dir_sep(sb.buf[sb.len - 1]))
- strbuf_addch(&sb, '/');
- strbuf_addstr(&sb, last_elem);
- free(last_elem);
- last_elem = NULL;
- }
-
- if (!lstat(sb.buf, &st) && S_ISLNK(st.st_mode)) {
- struct strbuf next_sb = STRBUF_INIT;
- ssize_t len = strbuf_readlink(&next_sb, sb.buf, 0);
+ len = strbuf_readlink(&symlink, resolved->buf,
+ st.st_size);
if (len < 0) {
if (die_on_error)
die_errno("Invalid symlink '%s'",
- sb.buf);
+ resolved->buf);
else
goto error_out;
}
- strbuf_swap(&sb, &next_sb);
- strbuf_release(&next_sb);
- } else
- break;
+
+ if (is_absolute_path(symlink.buf)) {
+ /* absolute symlink; set resolved to root */
+ get_root_part(resolved, &symlink);
+ } else {
+ /*
+ * relative symlink
+ * strip off the last component since it will
+ * be replaced with the contents of the symlink
+ */
+ strip_last_component(resolved);
+ }
+
+ /*
+ * if there are still remaining components to resolve
+ * then append them to symlink
+ */
+ if (remaining.len) {
+ strbuf_addch(&symlink, '/');
+ strbuf_addbuf(&symlink, &remaining);
+ }
+
+ /*
+ * use the symlink as the remaining components that
+ * need to be resloved
+ */
+ strbuf_swap(&symlink, &remaining);
+ }
}
- retval = sb.buf;
+ retval = resolved->buf;
+
error_out:
- free(last_elem);
- if (cwd.len && chdir(cwd.buf))
- die_errno("Could not change back to '%s'", cwd.buf);
- strbuf_release(&cwd);
+ strbuf_release(&remaining);
+ strbuf_release(&next);
+ strbuf_release(&symlink);
+
+ if (!retval)
+ strbuf_reset(resolved);
return retval;
}
const char *real_path(const char *path)
{
- return real_path_internal(path, 1);
+ static struct strbuf realpath = STRBUF_INIT;
+ return strbuf_realpath(&realpath, path, 1);
}
const char *real_path_if_valid(const char *path)
{
- return real_path_internal(path, 0);
+ static struct strbuf realpath = STRBUF_INIT;
+ return strbuf_realpath(&realpath, path, 0);
+}
+
+char *real_pathdup(const char *path, int die_on_error)
+{
+ struct strbuf realpath = STRBUF_INIT;
+ char *retval = NULL;
+
+ if (strbuf_realpath(&realpath, path, die_on_error))
+ retval = strbuf_detach(&realpath, NULL);
+
+ strbuf_release(&realpath);
+
+ return retval;
}
/*
@@ -152,6 +239,13 @@ const char *absolute_path(const char *path)
return sb.buf;
}
+char *absolute_pathdup(const char *path)
+{
+ struct strbuf sb = STRBUF_INIT;
+ strbuf_add_absolute_path(&sb, path);
+ return strbuf_detach(&sb, NULL);
+}
+
/*
* Unlike prefix_path, this should be used if the named file does
* not have to interact with index entry; i.e. name of a random file