Look for input files relative to executable path instead of cwd (#11)

* Change default input files location to be relative to executable

Include/42.h

@@ -55,6 +55,9 @@ EXTERN long Nmatl;
 /* Number of geometric objects */
 EXTERN long Ngeom;
 
+#define STRINGIZE(x) #x
+#define STRINGIZE_VALUE_OF(x) STRINGIZE(x)
+
 EXTERN char InOutPath[80];
 EXTERN char ModelPath[80];
 EXTERN char CmdFileName[80];

Kit/Include/iokit.h

@@ -31,13 +31,16 @@
 #include <fcntl.h>
 #ifdef _WIN32
    #include <winsock2.h>
+   extern char *_pgmptr;
+   #define OS_SEP '\\'
 #else
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <netinet/tcp.h>
    #include <netdb.h>
    /* Finesse winsock SOCKET datatype */
    #define SOCKET int
+   #define OS_SEP '/'
 #endif
 /* #include <sys/un.h> */
 
@@ -49,6 +52,10 @@ int FileToString(const char *file_name, char **result_string,
 SOCKET InitSocketServer(int Port, int AllowBlocking);
 SOCKET InitSocketClient(const char *hostname, int Port, int AllowBlocking);
 
+void SplitPath(char *path_file, char **path, char **file);
+void GetExecutablePath(char *path, size_t bufsize);
+void AddTrailingSlash(char *path);
+
 /*
 ** #ifdef __cplusplus
 ** }

Kit/Source/iokit.c

@@ -278,6 +278,75 @@ SOCKET InitSocketClient(const char *hostname, int Port,int AllowBlocking)
 #endif /* _WIN32 */
 }
 
+/**
+ * Splits the `path_file` into a directory part: `path`, and file part: `file`
+ * If `path_file` is just a filename with no containing folder, `path` will be a 0 length string.
+*/
+void SplitPath(char *path_file, char **path, char **file) {
+   *path = (char *)malloc(strlen(path_file));
+   // file = (char *)malloc(strlen(path_file));
+   strcpy(*path, path_file);
+   char *pos = strrchr(*path, OS_SEP);
+   if (NULL == pos) {
+      *file = strdup(path_file);
+      (*path)[0] = '\0';
+   } else {
+      *pos = '\0';
+      *file = strdup(pos + 1);
+   }
+}
+
+/**
+ * Attempts to retrieve the full path to the currently running executable
+ * and populates `path` with it. Uses `max_path_len` to avoid overrunning `path`
+ * `max_path_len` is the total size of `path`, which means it includes the
+ * null terminating character.
+*/
+void GetExecutablePath(char *path, size_t max_path_len) {
+   ssize_t len;
+   memset(path, 0, max_path_len);
+#if defined(_WIN32)
+   strncpy(path, _pgmptr, max_path_len);
+   len = strlen(path);
+#else
+   len = readlink("/proc/self/exe", path, max_path_len);
+   if (len < 0) {
+     printf("Error: error when getting executable path. Exiting.\n");
+     exit(EXIT_FAILURE);
+   }
+#endif
+   if (len >= max_path_len) {
+     printf("Error: executable path received too long for file path buffer. Exiting.\n");
+     exit(EXIT_FAILURE);
+   }
+}
+
+/**
+ * Looks for a trailing slash in `path`; if one isn't found it appends one to `path`
+*/
+void AddTrailingSlash(char *path) {
+  char *end = strchr(path, '\0');
+  if (end == NULL) {
+    printf(
+        "Error: path provided contains no null terminating character. "
+        "Exiting.\n");
+    exit(EXIT_FAILURE);
+   }
+
+   char *slash = strrchr(path, OS_SEP);
+   if (slash != NULL) {
+      size_t diff = end - slash;
+      if (diff == 1) {
+         return;
+      }
+   }
+
+   char *sep = (char *)malloc(3);
+   sprintf(sep, "%c", OS_SEP);
+   strcat(path, sep);
+   free(sep);
+}
+
 /* #ifdef __cplusplus
 ** }
 ** #endif

Makefile

@@ -48,6 +48,12 @@ GMSECFLAG =
 RBTFLAG = 
 #RBTFLAG = -D _ENABLE_RBT_
 
+DEFAULT_CASE_PATH = 
+#DEFAULT_CASE_PATH = -D _DEFAULT_CASE_PATH_=./InOut
+
+DEFAULT_MODEL_PATH = 
+#DEFAULT_MODEL_PATH = -D _DEFAULT_MODEL_PATH_=./Model
+
 ifeq ($(strip $(GMSECFLAG)),)
    GMSECDIR =
    GMSECINC =
@@ -243,7 +249,7 @@ $(OBJ)AppWriteToSocket.o $(OBJ)AppReadFromSocket.o $(OBJ)AppWriteToFile.o
 #ANSIFLAGS = -Wstrict-prototypes -pedantic -ansi -Werror
 ANSIFLAGS =
 
-CFLAGS = -fpic -Wall -Wshadow -Wno-deprecated $(XWARN) -g  $(ANSIFLAGS) $(GLINC) $(CINC) -I $(INC) -I $(KITINC) -I $(KITSRC) -I $(RBTSRC) $(GMSECINC) -O0 $(ARCHFLAG) $(GUIFLAG) $(GUI_LIB) $(SHADERFLAG) $(CFDFLAG) $(FFTBFLAG) $(GSFCFLAG) $(GMSECFLAG) $(STANDALONEFLAG) $(RBTFLAG)
+CFLAGS = -fpic -Wall -Wshadow -Wno-deprecated $(XWARN) -g  $(ANSIFLAGS) $(GLINC) $(CINC) -I $(INC) -I $(KITINC) -I $(KITSRC) -I $(RBTSRC) $(GMSECINC) -O0 $(ARCHFLAG) $(GUIFLAG) $(GUI_LIB) $(SHADERFLAG) $(CFDFLAG) $(FFTBFLAG) $(GSFCFLAG) $(GMSECFLAG) $(STANDALONEFLAG) $(RBTFLAG) $(DEFAULT_CASE_PATH) $(DEFAULT_MODEL_PATH)
 
 
 ##########################  Rules to link 42  #############################

Source/42init.c

@@ -4368,8 +4368,41 @@ void InitSim(int argc, char **argv)
          if (argc > 1) sprintf(InOutPath,"../../GSFC/RBT/%s/",argv[1]);
          if (argc > 2) sprintf(ModelPath,"../../GSFC/RBT/%s/",argv[2]);
       #else
-         sprintf(InOutPath,"./InOut/");
-         sprintf(ModelPath,"./Model/");
+         char *exec_name, *exec_dir, *exec_path;
+         exec_path = (char *)malloc(FILENAME_MAX);
+
+         GetExecutablePath(exec_path, FILENAME_MAX);
+         SplitPath(exec_path, &exec_dir, &exec_name);
+
+         if (strlen(exec_dir) == 0) {
+           printf("Error finding executable's containing folder. Exiting.");
+           exit(EXIT_FAILURE);
+         }
+
+         AddTrailingSlash(exec_dir);
+
+#ifndef _DEFAULT_CASE_PATH_
+         strcpy(InOutPath, exec_dir);
+         strcat(InOutPath, "examples/InOut");
+#else
+         sprintf(InOutPath, STRINGIZE_VALUE_OF(_DEFAULT_CASE_PATH_));
+#endif
+
+         AddTrailingSlash((char *)InOutPath);
+
+#ifndef _DEFAULT_MODEL_PATH_
+         strcpy(ModelPath, exec_dir);
+         strcat(ModelPath, "Model");
+#else
+         sprintf(ModelPath, STRINGIZE_VALUE_OF(_DEFAULT_MODEL_PATH_));
+#endif
+
+         AddTrailingSlash((char *)ModelPath);
+
+         free(exec_name);
+         free(exec_dir);
+         free(exec_path);
+
          if (argc > 1) sprintf(InOutPath,"./%s/",argv[1]);
          if (argc > 2) sprintf(ModelPath,"./%s/",argv[2]);
       #endif