Initial Alpine Version

1 files changed, 160 insertions, 0 deletions

diff --git a/pith/osdep/canaccess.c b/pith/osdep/canaccess.c
new file mode 100644
index 00000000..4d79c407
--- /dev/null
+++ b/pith/osdep/canaccess.c
@@ -0,0 +1,160 @@
+#if !defined(lint) && !defined(DOS)
+static char rcsid[] = "$Id: canaccess.c 769 2007-10-24 00:15:40Z hubert@u.washington.edu $";
+#endif
+
+/*
+ * ========================================================================
+ * Copyright 2006-2007 University of Washington
+ * Copyright 2013 Eduardo Chappa
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * ========================================================================
+ */
+
+#include <system.h>
+#include "bldpath.h"
+#include "fnexpand.h"
+#include "../charconv/utf8.h"
+#include "../charconv/filesys.h"
+#include "canaccess.h"
+
+
+/*
+ * Useful definitions
+ */
+#ifdef	_WINDOWS
+
+#define ACCESS_IN_CWD(F,M)	(can_access((F), (M)))
+#define	PATH_SEP		';'
+#define	FILE_SEP		'\\'
+
+#else  /* UNIX */
+
+#define ACCESS_IN_CWD(F,M)	(-1)
+#define	PATH_SEP		':'
+#define	FILE_SEP		'/'
+
+#endif /* UNIX */
+
+
+
+/*
+ *     Check if we can access a file in a given way
+ *
+ * Args: file      -- The file to check
+ *       mode      -- The mode ala the access() system call, see ACCESS_EXISTS
+ *                    and friends in alpine.h.
+ *
+ * Result: returns 0 if the user can access the file according to the mode,
+ *         -1 if he can't (and errno is set).
+ *
+ *
+ */
+int
+can_access(char *file, int mode)
+{
+#ifdef	_WINDOWS
+    struct stat buf;
+
+    /*
+     * NOTE: The WinNT access call returns that every directory is readable and
+     * writable. We actually want to know if the write is going to fail, so we
+     * try it. We don't read directories in Windows so we skip implementing that.
+     */
+    if(mode & WRITE_ACCESS && file && !our_stat(file, &buf) && (buf.st_mode & S_IFMT) == S_IFDIR){
+	char *testname;
+	int   fd;
+	size_t l = 0;
+
+	/*
+	 * We'd like to just call temp_nam here, since it creates a file
+	 * and does what we want. However, temp_nam calls us!
+	 */
+	if((testname = malloc(MAXPATH * sizeof(char)))){
+	    strncpy(testname, file, MAXPATH-1);
+	    testname[MAXPATH-1] = '\0';
+	    if(testname[0] && testname[(l=strlen(testname))-1] != '\\' &&
+	       l+1 < MAXPATH){
+		l++;
+		strncat(testname, "\\", MAXPATH-strlen(testname)-1);
+		testname[MAXPATH-1] = '\0';
+	    }
+	    
+	    if(l+8 < MAXPATH &&
+	       strncat(testname, "caXXXXXX", MAXPATH-strlen(testname)-1) && mktemp(testname)){
+		if((fd = our_open(testname, O_CREAT|O_EXCL|O_WRONLY|O_BINARY, 0600)) >= 0){
+		    (void)close(fd);
+		    our_unlink(testname);
+		    free(testname);
+		    /* success, drop through to access call */
+		}
+		else{
+		    free(testname);
+		    /* can't write in the directory */
+		    return(-1);
+		}
+	    }
+	    else{
+		free(testname);
+		return(-1);
+	    }
+	}
+    }
+    if(mode & EXECUTE_ACCESS)    /* Windows access has no execute mode */
+      mode &= ~EXECUTE_ACCESS;   /* and crashes because of it */
+#endif /* WINDOWS */
+
+    return(our_access(file, mode));
+}
+
+
+/*----------------------------------------------------------------------
+       Check if we can access a file in a given way in the given path
+
+   Args: path     -- The path to look for "file" in
+	 file      -- The file to check
+         mode      -- The mode ala the access() system call, see ACCESS_EXISTS
+                      and friends in alpine.h.
+
+ Result: returns 0 if the user can access the file according to the mode,
+         -1 if he can't (and errno is set).
+ ----*/
+int
+can_access_in_path(char *path, char *file, int mode)
+{
+    char tmp[MAXPATH];
+    int  rv = -1;
+
+    if(!path || !*path || is_rooted_path(file)){
+	rv = can_access(file, mode);
+    }
+    else if(is_homedir_path(file)){
+	strncpy(tmp, file, sizeof(tmp));
+	tmp[sizeof(tmp)-1] = '\0';
+	rv = fnexpand(tmp, sizeof(tmp)) ? can_access(tmp, mode) : -1;
+    }
+    else if((rv = ACCESS_IN_CWD(file,mode)) < 0){
+	char path_copy[MAXPATH + 1], *p, *t;
+
+	if(strlen(path) < MAXPATH){
+	    strncpy(path_copy, path, sizeof(path_copy));
+	    path_copy[sizeof(path_copy)-1] = '\0';
+
+	    for(p = path_copy; p && *p; p = t){
+		if((t = strchr(p, PATH_SEP)) != NULL)
+		  *t++ = '\0';
+
+		snprintf(tmp, sizeof(tmp), "%s%c%s", p, FILE_SEP, file);
+		if((rv = can_access(tmp, mode)) == 0)
+		  break;
+	    }
+	}
+    }
+
+    return(rv);
+}