strmode: Remove strcpy usage

The code can be simplified to avoid strcpy usage. While not exactly a
much safer approach by manually adjusting characters in a string, this
attempt reduces size of libarchive and avoids unneeded copy operations.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

diff --git a/libarchive/archive_entry_strmode.c b/libarchive/archive_entry_strmode.c
index 5faa2faeefa09f119c2bf7c05fdb933a3ad19b4a..22171992dd492a93dba170a1496c07150dd6c5c8 100644 (file)
--- a/libarchive/archive_entry_strmode.c
+++ b/libarchive/archive_entry_strmode.c
@@ -28,9 +28,6 @@
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
-#ifdef HAVE_STRING_H
-#include <string.h>
-#endif
 
 #include "archive_entry.h"
 #include "archive_entry_private.h"
@@ -38,16 +35,10 @@
 const char *
 archive_entry_strmode(struct archive_entry *entry)
 {
-       static const mode_t permbits[] =
-           { 0400, 0200, 0100, 0040, 0020, 0010, 0004, 0002, 0001 };
        char *bp = entry->strmode;
-       mode_t mode;
+       mode_t mask, mode;
        int i;
 
-       /* Fill in a default string, then selectively override. */
-       strcpy(bp, "?rwxrwxrwx ");
-
-       mode = archive_entry_mode(entry);
        switch (archive_entry_filetype(entry)) {
        case AE_IFREG:  bp[0] = '-'; break;
        case AE_IFBLK:  bp[0] = 'b'; break;
@@ -57,30 +48,22 @@ archive_entry_strmode(struct archive_entry *entry)
        case AE_IFSOCK: bp[0] = 's'; break;
        case AE_IFIFO:  bp[0] = 'p'; break;
        default:
-               if (archive_entry_hardlink(entry) != NULL) {
-                       bp[0] = 'h';
-                       break;
-               }
+               bp[0] = (archive_entry_hardlink(entry) != NULL) ? 'h' : '?';
+               break;
        }
 
-       for (i = 0; i < 9; i++)
-               if (!(mode & permbits[i]))
-                       bp[i+1] = '-';
+       mode = archive_entry_mode(entry);
+       for (i = 0, mask = 0400; i < 9; i++, mask >>= 1)
+               bp[i + 1] = (mode & mask) ? "rwx"[i % 3] : '-';
 
-       if (mode & S_ISUID) {
-               if (mode & 0100) bp[3] = 's';
-               else bp[3] = 'S';
-       }
-       if (mode & S_ISGID) {
-               if (mode & 0010) bp[6] = 's';
-               else bp[6] = 'S';
-       }
-       if (mode & S_ISVTX) {
-               if (mode & 0001) bp[9] = 't';
-               else bp[9] = 'T';
-       }
-       if (archive_entry_acl_types(entry) != 0)
-               bp[10] = '+';
+       if (mode & S_ISUID)
+               bp[3] = (mode & 0100) ? 's' : 'S';
+       if (mode & S_ISGID)
+               bp[6] = (mode & 0010) ? 's' : 'S';
+       if (mode & S_ISVTX)
+               bp[9] = (mode & 0001) ? 't' : 'T';
+       bp[10] = (archive_entry_acl_types(entry) != 0) ? '+' : ' ';
+       bp[11] = '\0';
 
        return (bp);
 }