added "xschem samefile" command to verify if 2 files are the same entity by comparing inodes, pwd_dir set in xinit.c to $env(PWD) if PWD var is defined as it does not dereference symlinks

src/actions.c

@@ -440,6 +440,21 @@ const char *get_file_path(char *f)
   return tclresult();
 }
 
+
+int samefile(const char *fa, const char *fb)
+{
+
+   struct stat a, b;
+   int statusa, statusb;
+
+   statusa = stat(fa, &a);
+   statusb = stat(fb, &b);
+   if(statusa == 0 && statusb == 0 && a.st_ino == b.st_ino) {
+     return 1;
+   }
+   return 0; /* not same of one of the two not existing */
+}
+
 int save(int confirm) /* 20171006 add confirm */
 {
      int cancel;

src/save.c

@@ -901,6 +901,7 @@ void make_symbol(void)
 
 }
 
+/* ALWAYS call with absolute path in schname!!! */
 int save_schematic(const char *schname) /* 20171020 added return value */
 {
   FILE *fd;
@@ -959,7 +960,7 @@ void link_symbols_to_instances(void) /* 20150326 separated from load_schematic()
   }
 
 }
-
+/* ALWAYS use absolute pathname for filename!!! */
 void load_schematic(int load_symbols, const char *filename, int reset_undo) /* 20150327 added reset_undo */
 {
   FILE *fd;

src/scheduler.c

@@ -1110,6 +1110,13 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
    }
  }
 
+ else if(!strcmp(argv[1], "samefile") && argc == 4) {
+   int r;
+   r = samefile(argv[2], argv[3]);
+   Tcl_ResetResult(interp);
+   Tcl_AppendResult(interp, r ? "1" : "0" , NULL);
+ }
+
  else if(!strcmp(argv[1],"create_plot_cmd") ) {
    if(argc>2) {
      if(!strcmp(argv[2], "gaw")) {
@@ -1220,7 +1227,7 @@ int xschem(ClientData clientdata, Tcl_Interp *interp, int argc, const char * arg
       unselect_all();
       remove_symbols();
       /* load_symbol(argv[2]); */
-      load_schematic(0, argv[2], 1);
+      load_schematic(0, abs_sym_path(argv[2], ""), 1);
       my_strdup(374, &xctx.sch_path[xctx.currsch],".");
       xctx.sch_inst_number[xctx.currsch] = 1;
       zoom_full(1, 0);

src/xinit.c

@@ -1433,17 +1433,15 @@ int Tcl_AppInit(Tcl_Interp *inter)
 
  enable_layers();
 
+ /* prefer using env(PWD) if existing since it does not dereference symlinks */
+ if(tcleval("info exists env(PWD)")[0] == '1') {
+   my_snprintf(pwd_dir, S(pwd_dir), "%s", tclgetvar("env(PWD)"));
+ }
+
  if(filename) {
     char f[PATH_MAX];
     if(filename[0] !='/') {
-      /* prefer not use pwd_dir since it dereferences symlinks
-                                             |   
-                                            \|/  */
-      if(tcleval("info exists env(PWD)")[0] == '1') {
-        my_snprintf(f, S(f), "%s/%s", tclgetvar("env(PWD)"), filename);
-      } else {
-        my_snprintf(f, S(f), "%s/%s", pwd_dir, filename);
-      }
+      my_snprintf(f, S(f), "%s/%s", pwd_dir, filename);
     } else {
       my_snprintf(f, S(f), "%s", filename);
     }

src/xschem.h

@@ -717,6 +717,7 @@ extern void schematic_in_new_window(void);
 extern void symbol_in_new_window(void);
 extern void new_window(const char *cell, int symbol);
 extern void ask_new_file(void);
+extern int samefile(const char *fa, const char *fb);
 extern void saveas(const char *f, int type);
 extern const char *get_file_path(char *f);
 extern int save(int confirm);

src/xschem.tcl

@@ -2625,7 +2625,7 @@ proc rel_sym_path {symbol} {
       break
     }
   }
-  if { ![string compare $name {} ] } {
+  if {$name eq {} } {
     # no known lib, so return full path
     set name ${symbol}
   }
@@ -2655,8 +2655,8 @@ proc abs_sym_path {fname {ext {} } } {
     while { [regsub {^\./} $fname {} fname] } {}
     if { $fname eq {} } { set fname . } 
 
-    # if fname is just "."  or "./" return $current_dirname
-    if {[regexp {^\./*$} $fname] } {
+    # if fname is just "." return $current_dirname
+    if {[regexp {^\.$} $fname] } {
       return $current_dirname
     }
   }