bstr.[ch], path.[ch]: add string and path handling functions

Add some new string and path handling functions to be used in
following commits.

Use new path handling functions to simplify find_files().

bstr.c

@@ -18,6 +18,10 @@
 
 #include <string.h>
 #include <libavutil/avutil.h>
+#include <assert.h>
+
+#include "talloc.h"
+
 #include "bstr.h"
 
 int bstrcmp(struct bstr str1, struct bstr str2)
@@ -49,3 +53,90 @@ int bstrcasecmp(struct bstr str1, struct bstr str2)
     }
     return ret;
 }
+
+int bstrchr(struct bstr str, int c)
+{
+    for (int i = 0; i < str.len; i++)
+        if (str.start[i] == c)
+            return i;
+    return -1;
+}
+
+struct bstr bstr_strip(struct bstr str)
+{
+    while (str.len && isspace(*str.start)) {
+        str.start++;
+        str.len--;
+    }
+    while (str.len && isspace(str.start[str.len - 1]))
+        str.len--;
+    return str;
+}
+
+struct bstr bstr_split(struct bstr str, char *sep, struct bstr *rest)
+{
+    int start, end;
+    for (start = 0; start < str.len; start++)
+        if (!strchr(sep, str.start[start]))
+            break;
+    for (end = start; end < str.len; end++)
+        if (strchr(sep, str.start[end]))
+            break;
+    if (rest) {
+        *rest = bstr_cut(str, end);
+    }
+    str.start += start;
+    str.len = end - start;
+    return str;
+}
+
+
+struct bstr bstr_splice(struct bstr str, int start, int end)
+{
+    if (start < 0)
+        start += str.len;
+    if (end < 0)
+        end += str.len;
+    end = FFMIN(end, str.len);
+    start = FFMAX(start, 0);
+    if (start >= end)
+        return (struct bstr){NULL, 0};
+    str.start += start;
+    str.len = end - start;
+    return str;
+}
+
+long long bstrtoll(struct bstr str, struct bstr *rest, int base)
+{
+    char buf[51];
+    int len = FFMIN(str.len, 50);
+    memcpy(buf, str.start, len);
+    buf[len] = 0;
+    char *endptr;
+    long long r = strtoll(buf, &endptr, base);
+    if (rest)
+        *rest = bstr_cut(str, endptr - buf);
+    return r;
+}
+
+struct bstr *bstr_splitlines(void *talloc_ctx, struct bstr str)
+{
+    if (str.len == 0)
+        return NULL;
+    int count = 0;
+    for (int i = 0; i < str.len; i++)
+        if (str.start[i] == '\n')
+            count++;
+    if (str.start[str.len - 1] != '\n')
+        count++;
+    struct bstr *r = talloc_array_ptrtype(talloc_ctx, r, count);
+    unsigned char *p = str.start;
+    for (int i = 0; i < count - 1; i++) {
+        r[i].start = p;
+        while (*p++ != '\n');
+        r[i].len = p - r[i].start;
+    }
+    r[count - 1].start = p;
+    r[count - 1].len = str.start + str.len - p;
+    return r;
+}

bstr.h

@@ -22,18 +22,50 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <string.h>
+#include <stdbool.h>
 
+#include "talloc.h"
+
+/* NOTE: 'len' is size_t, but most string-handling functions below assume
+ * that input size has been sanity checked and len fits in an int.
+ */
 struct bstr {
-    const uint8_t *start;
+    unsigned char *start;
     size_t len;
 };
 
 int bstrcmp(struct bstr str1, struct bstr str2);
 int bstrcasecmp(struct bstr str1, struct bstr str2);
+int bstrchr(struct bstr str, int c);
+struct bstr *bstr_splitlines(void *talloc_ctx, struct bstr str);
+struct bstr bstr_strip(struct bstr str);
+struct bstr bstr_split(struct bstr str, char *sep, struct bstr *rest);
+struct bstr bstr_splice(struct bstr str, int start, int end);
+long long bstrtoll(struct bstr str, struct bstr *rest, int base);
+
+static inline struct bstr bstr_cut(struct bstr str, int n)
+{
+    return (struct bstr){str.start + n, str.len - n};
+}
+
+static inline bool bstr_startswith(struct bstr str, struct bstr prefix)
+{
+    if (str.len < prefix.len)
+        return false;
+    return !memcmp(str.start, prefix.start, prefix.len);
+}
+
+static inline char *bstrdup0(void *talloc_ctx, struct bstr str)
+{
+    // cast is live555 C++ compilation workaround
+    return talloc_strndup(talloc_ctx, (char *)str.start, str.len);
+}
 
 // Create bstr compound literal from null-terminated string
-#define BSTR(s) (struct bstr){(s), (s) ? strlen(s) : 0}
+#define BSTR(s) (struct bstr){(char *)(s), (s) ? strlen(s) : 0}
 // create a pair (not single value!) for "%.*s" printf syntax
 #define BSTR_P(bstr) (int)((bstr).len), (bstr).start
 
+#define WHITESPACE " \f\n\r\t\v"
+
 #endif /* MPLAYER_BSTR_H */

osdep/findfiles.c

@@ -22,38 +22,18 @@
 #include <assert.h>
 
 #include "talloc.h"
-
-#if defined(__MINGW32__) || defined(__CYGWIN__)
-static const char dir_separators[] = "/\\:";
-#else
-static const char dir_separators[] = "/";
-#endif
+#include "path.h"
+#include "bstr.h"
 
 char **find_files(const char *original_file, const char *suffix,
                   int *num_results_ptr)
 {
     void *tmpmem = talloc_new(NULL);
-    char *fname = talloc_strdup(tmpmem, original_file);
-    char *basename = NULL;
-    char *next = fname;
-    while (1) {
-        next = strpbrk(next, dir_separators);
-        if (!next)
-            break;
-        basename = next++;
-    }
-    char *directory;
-    if (basename) {
-        directory = fname;
-        *basename++ = 0;
-    } else {
-        directory = ".";
-        basename = fname;
-    }
-
-
+    char *basename = mp_basename(original_file);
+    struct bstr directory = mp_dirname(original_file);
     char **results = talloc_size(NULL, 0);
-    DIR *dp = opendir(directory);
+    char *dir_zero = bstrdup0(tmpmem, directory);
+    DIR *dp = opendir(dir_zero);
     struct dirent *ep;
     char ***names_by_matchlen = talloc_array(tmpmem, char **,
                                              strlen(basename) + 1);
@@ -68,7 +48,7 @@ char **find_files(const char *original_file, const char *suffix,
         if (!strcmp(ep->d_name, basename))
             continue;
 
-        char *name = talloc_asprintf(results, "%s/%s", directory, ep->d_name);
+        char *name = mp_path_join(results, directory, BSTR(ep->d_name));
         char *s1 = ep->d_name;
         char *s2 = basename;
         int matchlen = 0;

path.c

@@ -26,6 +26,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdbool.h>
 #include "config.h"
 #include "mp_msg.h"
 #include "path.h"
@@ -42,6 +43,8 @@
 #include <sys/cygwin.h>
 #endif
 
+#include "talloc.h"
+
 #include "osdep/osdep.h"
 
 char *get_path(const char *filename){
@@ -194,7 +197,7 @@ void set_codec_path(const char *path)
     needs_free = 1;
 }
 
-const char *mp_basename(const char *path)
+char *mp_basename(const char *path)
 {
     char *s;
 
@@ -207,5 +210,41 @@ const char *mp_basename(const char *path)
         path = s + 1;
 #endif
     s = strrchr(path, '/');
-    return s ? s + 1 : path;
+    return s ? s + 1 : (char *)path;
+}
+
+struct bstr mp_dirname(const char *path)
+{
+    struct bstr ret = {(uint8_t *)path, mp_basename(path) - path};
+    if (ret.len == 0)
+        return BSTR(".");
+    return ret;
+}
+
+char *mp_path_join(void *talloc_ctx, struct bstr p1, struct bstr p2)
+{
+    if (p1.len == 0)
+        return bstrdup0(talloc_ctx, p2);
+    if (p2.len == 0)
+        return bstrdup0(talloc_ctx, p1);
+
+#if HAVE_DOS_PATHS
+    if (p2.len >= 2 && p2.start[1] == ':'
+        || p2.start[0] == '\\' || p2.start[0] == '/')
+#else
+    if (p2.start[0] == '/')
+#endif
+        return bstrdup0(talloc_ctx, p2);   // absolute path
+
+    bool have_separator;
+    int endchar1 = p1.start[p1.len - 1];
+#if HAVE_DOS_PATHS
+    have_separator = endchar1 == '/' || endchar1 == '\\'
+        || p1.len == 2 && endchar1 == ':';     // "X:" only
+#else
+    have_separator = endchar1 == '/';
+#endif
+
+    return talloc_asprintf(talloc_ctx, "%.*s%s%.*s", BSTR_P(p1),
+                           have_separator ? "" : "/", BSTR_P(p2));
 }

path.h

@@ -21,11 +21,27 @@
 #ifndef MPLAYER_PATH_H
 #define MPLAYER_PATH_H
 
+#include "bstr.h"
+
 extern char *codec_path;
 
 char *get_path(const char *filename);
 void set_path_env(void);
 void set_codec_path(const char *path);
-const char *mp_basename(const char *path);
+
+// Return pointer to filename part of path
+
+char *mp_basename(const char *path);
+
+/* Return struct bstr referencing directory part of path, or if that
+ * would be empty, ".".
+ */
+struct bstr mp_dirname(const char *path);
+
+/* Join two path components and return a newly allocated string
+ * for the result. '/' is inserted between the components if needed.
+ * If p2 is an absolute path then the value of p1 is ignored.
+ */
+char *mp_path_join(void *talloc_ctx, struct bstr p1, struct bstr p2);
 
 #endif /* MPLAYER_PATH_H */