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authorLennart Poettering <lennart@poettering.net>2010-01-29 01:48:57 +0100
committerLennart Poettering <lennart@poettering.net>2010-01-29 01:48:57 +0100
commit4fe88d28a4cfa504c1f2362d4a7030fae4c4af29 (patch)
tree7cbbb94f12dffba4e3105657a5c324198c99f10b
parent25ac040b489a7bf9c8608308a721d32e20a22911 (diff)
add various escaping/path handling utility functions
-rw-r--r--util.c323
-rw-r--r--util.h14
2 files changed, 337 insertions, 0 deletions
diff --git a/util.c b/util.c
index b166f328b2..19375aebca 100644
--- a/util.c
+++ b/util.c
@@ -553,3 +553,326 @@ char hexchar(int x) {
return table[x & 15];
}
+
+int unhexchar(char c) {
+
+ if (c >= '0' && c <= '9')
+ return c - '0';
+
+ if (c >= 'a' && c <= 'f')
+ return c - 'a';
+
+ if (c >= 'A' && c <= 'F')
+ return c - 'A';
+
+ return -1;
+}
+
+char octchar(int x) {
+ return '0' + (x & 7);
+}
+
+int unoctchar(char c) {
+
+ if (c >= '0' && c <= '7')
+ return c - '0';
+
+ return -1;
+}
+
+char *cescape(const char *s) {
+ char *r, *t;
+ const char *f;
+
+ assert(s);
+
+ /* Does C style string escaping. */
+
+ if (!(r = new(char, strlen(s)*4 + 1)))
+ return NULL;
+
+ for (f = s, t = r; *f; f++)
+
+ switch (*f) {
+
+ case '\a':
+ *(t++) = '\\';
+ *(t++) = 'a';
+ break;
+ case '\b':
+ *(t++) = '\\';
+ *(t++) = 'b';
+ break;
+ case '\f':
+ *(t++) = '\\';
+ *(t++) = 'f';
+ break;
+ case '\n':
+ *(t++) = '\\';
+ *(t++) = 'n';
+ break;
+ case '\r':
+ *(t++) = '\\';
+ *(t++) = 'r';
+ break;
+ case '\t':
+ *(t++) = '\\';
+ *(t++) = 't';
+ break;
+ case '\v':
+ *(t++) = '\\';
+ *(t++) = 'v';
+ break;
+ case '\\':
+ *(t++) = '\\';
+ *(t++) = '\\';
+ break;
+ case '"':
+ *(t++) = '\\';
+ *(t++) = '"';
+ break;
+ case '\'':
+ *(t++) = '\\';
+ *(t++) = '\'';
+ break;
+
+ default:
+ /* For special chars we prefer octal over
+ * hexadecimal encoding, simply because glib's
+ * g_strescape() does the same */
+ if ((*f < ' ') || (*f >= 127)) {
+ *(t++) = '\\';
+ *(t++) = octchar((unsigned char) *f >> 6);
+ *(t++) = octchar((unsigned char) *f >> 3);
+ *(t++) = octchar((unsigned char) *f);
+ } else
+ *(t++) = *f;
+ break;
+ }
+
+ *t = 0;
+
+ return r;
+}
+
+char *cunescape(const char *s) {
+ char *r, *t;
+ const char *f;
+
+ assert(s);
+
+ /* Undoes C style string escaping */
+
+ if (!(r = new(char, strlen(s)+1)))
+ return r;
+
+ for (f = s, t = r; *f; f++) {
+
+ if (*f != '\\') {
+ *(t++) = *f;
+ continue;
+ }
+
+ f++;
+
+ switch (*f) {
+
+ case 'a':
+ *(t++) = '\a';
+ break;
+ case 'b':
+ *(t++) = '\b';
+ break;
+ case 'f':
+ *(t++) = '\f';
+ break;
+ case 'n':
+ *(t++) = '\n';
+ break;
+ case 'r':
+ *(t++) = '\r';
+ break;
+ case 't':
+ *(t++) = '\t';
+ break;
+ case 'v':
+ *(t++) = '\v';
+ break;
+ case '\\':
+ *(t++) = '\\';
+ break;
+ case '"':
+ *(t++) = '"';
+ break;
+ case '\'':
+ *(t++) = '\'';
+ break;
+
+ case 'x': {
+ /* hexadecimal encoding */
+ int a, b;
+
+ if ((a = unhexchar(f[1])) < 0 ||
+ (b = unhexchar(f[2])) < 0) {
+ /* Invalid escape code, let's take it literal then */
+ *(t++) = '\\';
+ *(t++) = 'x';
+ } else {
+ *(t++) = (char) ((a << 4) | b);
+ f += 2;
+ }
+
+ break;
+ }
+
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7': {
+ /* octal encoding */
+ int a, b, c;
+
+ if ((a = unoctchar(f[0])) < 0 ||
+ (b = unoctchar(f[1])) < 0 ||
+ (c = unoctchar(f[2])) < 0) {
+ /* Invalid escape code, let's take it literal then */
+ *(t++) = '\\';
+ *(t++) = f[0];
+ } else {
+ *(t++) = (char) ((a << 6) | (b << 3) | c);
+ f += 2;
+ }
+
+ break;
+ }
+
+ case 0:
+ /* premature end of string.*/
+ *(t++) = '\\';
+ goto finish;
+
+ default:
+ /* Invalid escape code, let's take it literal then */
+ *(t++) = '\\';
+ *(t++) = 'f';
+ break;
+ }
+ }
+
+finish:
+ *t = 0;
+ return r;
+}
+
+
+char *xescape(const char *s, const char *bad) {
+ char *r, *t;
+ const char *f;
+
+ /* Escapes all chars in bad, in addition to \ and all special
+ * chars, in \xFF style escaping. May be reversed with
+ * cunescape. */
+
+ if (!(r = new(char, strlen(s)*4+1)))
+ return NULL;
+
+ for (f = s, t = r; *f; f++) {
+
+ if (*f < ' ' || *f >= 127 ||
+ *f == '\\' || strchr(bad, *f)) {
+ *(t++) = '\\';
+ *(t++) = 'x';
+ *(t++) = hexchar(*f >> 4);
+ *(t++) = hexchar(*f);
+ } else
+ *(t++) = *f;
+ }
+
+ *t = 0;
+
+ return r;
+}
+
+char *path_kill_slashes(char *path) {
+ char *f, *t;
+ bool slash = false;
+
+ /* Removes redundant inner and trailing slashes. Modifies the
+ * passed string in-place.
+ *
+ * ///foo///bar/ becomes /foo/bar
+ */
+
+ for (f = path, t = path; *f; f++) {
+
+ if (*f == '/') {
+ slash = true;
+ continue;
+ }
+
+ if (slash) {
+ slash = false;
+ *(t++) = '/';
+ }
+
+ *(t++) = *f;
+ }
+
+ /* Special rule, if we are talking of the root directory, a
+ trailing slash is good */
+
+ if (t == path && slash)
+ *(t++) = '/';
+
+ *t = 0;
+ return path;
+}
+
+bool path_startswith(const char *path, const char *prefix) {
+ assert(path);
+ assert(prefix);
+
+ if ((path[0] == '/') != (prefix[0] == '/'))
+ return false;
+
+ for (;;) {
+ size_t a, b;
+
+ path += strspn(path, "/");
+ prefix += strspn(prefix, "/");
+
+ if (*prefix == 0)
+ return true;
+
+ if (*path == 0)
+ return false;
+
+ a = strcspn(path, "/");
+ b = strcspn(prefix, "/");
+
+ if (a != b)
+ return false;
+
+ if (memcmp(path, prefix, a) != 0)
+ return false;
+
+ path += a;
+ prefix += b;
+ }
+}
+
+char *ascii_strlower(char *path) {
+ char *p;
+
+ assert(path);
+
+ for (p = path; *p; p++)
+ if (*p >= 'A' && *p <= 'Z')
+ *p = *p - 'A' + 'a';
+
+ return p;
+}
diff --git a/util.h b/util.h
index fcf380031d..32da179aee 100644
--- a/util.h
+++ b/util.h
@@ -106,5 +106,19 @@ char *strstrip(char *s);
char *file_in_same_dir(const char *path, const char *filename);
char hexchar(int x);
+int unhexchar(char c);
+char octchar(int x);
+int unoctchar(char c);
+
+char *cescape(const char *s);
+char *cunescape(const char *s);
+
+char *path_kill_slashes(char *path);
+
+bool path_startswith(const char *path, const char *prefix);
+
+char *ascii_strlower(char *path);
+
+char *xescape(const char *s, const char *bad);
#endif