bulk of file api implementation complete and working

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@2345 4e78687f-474d-0410-85f9-8d5e500ac6b2

7 files changed, 226 insertions, 89 deletions

diff --git a/src/Makefile.in b/src/Makefile.in
index dd32d94b..f02a0f52 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -102,8 +102,8 @@ am_libproj_la_OBJECTS = PJ_aeqd.lo PJ_gnom.lo PJ_laea.lo \
 	pj_open_lib.lo pj_param.lo pj_phi2.lo pj_pr_list.lo pj_qsfn.lo \
 	pj_strerrno.lo pj_tsfn.lo pj_units.lo pj_ctx.lo pj_log.lo \
 	pj_zpoly1.lo rtodms.lo vector1.lo pj_release.lo pj_gauss.lo \
-	PJ_healpix.lo PJ_natearth.lo pj_gc_reader.lo pj_gridcatalog.lo \
-	nad_cvt.lo nad_init.lo nad_intr.lo emess.lo \
+	PJ_healpix.lo PJ_natearth.lo pj_fileapi.lo pj_gc_reader.lo \
+	pj_gridcatalog.lo nad_cvt.lo nad_init.lo nad_intr.lo emess.lo \
 	pj_apply_gridshift.lo pj_datums.lo pj_datum_set.lo \
 	pj_transform.lo geocent.lo pj_utils.lo pj_gridinfo.lo \
 	pj_gridlist.lo jniproj.lo pj_mutex.lo pj_initcache.lo \
@@ -317,7 +317,7 @@ libproj_la_SOURCES = \
 	pj_open_lib.c pj_param.c pj_phi2.c pj_pr_list.c \
 	pj_qsfn.c pj_strerrno.c pj_tsfn.c pj_units.c pj_ctx.c pj_log.c \
 	pj_zpoly1.c rtodms.c vector1.c pj_release.c pj_gauss.c \
-	PJ_healpix.c PJ_natearth.c \
+	PJ_healpix.c PJ_natearth.c pj_fileapi.c \
 	\
 	pj_gc_reader.c pj_gridcatalog.c \
 	nad_cvt.c nad_init.c nad_intr.c emess.c emess.h \
@@ -601,6 +601,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_ellps.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_errno.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_factors.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_fileapi.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_fwd.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gauss.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/pj_gc_reader.Plo@am__quote@
diff --git a/src/nad_init.c b/src/nad_init.c
index bb62bd6f..84dc9867 100644
--- a/src/nad_init.c
+++ b/src/nad_init.c
@@ -82,18 +82,18 @@ static void swap_words( void *data_in, int word_size, int word_count )
 /*      Load the data portion of a ctable formatted grid.               */
 /************************************************************************/
 
-int nad_ctable_load( projCtx ctx, struct CTABLE *ct, FILE *fid )
+int nad_ctable_load( projCtx ctx, struct CTABLE *ct, PAFile fid )
 
 {
     int  a_size;
 
-    fseek( fid, sizeof(struct CTABLE), SEEK_SET );
+    pj_ctx_fseek( ctx, fid, sizeof(struct CTABLE), SEEK_SET );
 
     /* read all the actual shift values */
     a_size = ct->lim.lam * ct->lim.phi;
     ct->cvs = (FLP *) pj_malloc(sizeof(FLP) * a_size);
     if( ct->cvs == NULL 
-        || fread(ct->cvs, sizeof(FLP), a_size, fid) != a_size )
+        || pj_ctx_fread(ctx, ct->cvs, sizeof(FLP), a_size, fid) != a_size )
     {
         pj_dalloc( ct->cvs );
         ct->cvs = NULL;
@@ -113,7 +113,7 @@ int nad_ctable_load( projCtx ctx, struct CTABLE *ct, FILE *fid )
 /*      Read the header portion of a "ctable" format grid.              */
 /************************************************************************/
 
-struct CTABLE *nad_ctable_init( projCtx ctx, FILE * fid )
+struct CTABLE *nad_ctable_init( projCtx ctx, PAFile fid )
 {
     struct CTABLE *ct;
     int		id_end;
@@ -121,7 +121,7 @@ struct CTABLE *nad_ctable_init( projCtx ctx, FILE * fid )
     /* read the table header */
     ct = (struct CTABLE *) pj_malloc(sizeof(struct CTABLE));
     if( ct == NULL 
-        || fread( ct, sizeof(struct CTABLE), 1, fid ) != 1 )
+        || pj_ctx_fread( ctx, ct, sizeof(struct CTABLE), 1, fid ) != 1 )
     {
         pj_ctx_set_errno( ctx, -38 );
         return NULL;
@@ -155,18 +155,18 @@ struct CTABLE *nad_ctable_init( projCtx ctx, FILE * fid )
 /*      Load the data portion of a ctable2 formatted grid.              */
 /************************************************************************/
 
-int nad_ctable2_load( projCtx ctx, struct CTABLE *ct, FILE *fid )
+int nad_ctable2_load( projCtx ctx, struct CTABLE *ct, PAFile fid )
 
 {
     int  a_size;
 
-    fseek( fid, 160, SEEK_SET );
+    pj_ctx_fseek( ctx, fid, 160, SEEK_SET );
 
     /* read all the actual shift values */
     a_size = ct->lim.lam * ct->lim.phi;
     ct->cvs = (FLP *) pj_malloc(sizeof(FLP) * a_size);
     if( ct->cvs == NULL 
-        || fread(ct->cvs, sizeof(FLP), a_size, fid) != a_size )
+        || pj_ctx_fread(ctx, ct->cvs, sizeof(FLP), a_size, fid) != a_size )
     {
         pj_dalloc( ct->cvs );
         ct->cvs = NULL;
@@ -195,13 +195,13 @@ int nad_ctable2_load( projCtx ctx, struct CTABLE *ct, FILE *fid )
 /*      Read the header portion of a "ctable2" format grid.             */
 /************************************************************************/
 
-struct CTABLE *nad_ctable2_init( projCtx ctx, FILE * fid )
+struct CTABLE *nad_ctable2_init( projCtx ctx, PAFile fid )
 {
     struct CTABLE *ct;
     int		id_end;
     char        header[160];
 
-    if( fread( header, sizeof(header), 1, fid ) != 1 )
+    if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
     {
         pj_ctx_set_errno( ctx, -38 );
         return NULL;
@@ -268,7 +268,7 @@ struct CTABLE *nad_init(projCtx ctx, char *name)
 {
     char 	fname[MAX_PATH_FILENAME+1];
     struct CTABLE *ct;
-    FILE 	*fid;
+    PAFile      fid;
 
     ctx->last_errno = 0;
 
@@ -290,7 +290,7 @@ struct CTABLE *nad_init(projCtx ctx, char *name)
         }
     }
 
-    fclose(fid);
+    pj_ctx_fclose(ctx, fid);
     return ct;
 }
 
diff --git a/src/pj_gc_reader.c b/src/pj_gc_reader.c
index e22aa993..f944b0f1 100644
--- a/src/pj_gc_reader.c
+++ b/src/pj_gc_reader.c
@@ -32,7 +32,7 @@
 #include <projects.h>
 #include <string.h>
 
-static int pj_gc_readentry( projCtx ctx, FILE *fp, PJ_GridCatalogEntry *entry );
+static int pj_gc_readentry(projCtx ctx, PAFile fp, PJ_GridCatalogEntry *entry);
 static void pj_gc_sortcatalog( projCtx ctx, PJ_GridCatalog *catalog );
 
 /************************************************************************/
@@ -43,7 +43,7 @@ static void pj_gc_sortcatalog( projCtx ctx, PJ_GridCatalog *catalog );
 
 PJ_GridCatalog *pj_gc_readcatalog( projCtx ctx, const char *catalog_name )
 {
-    FILE *fp;
+    PAFile fp;
     PJ_GridCatalog *catalog;
     int entry_max, err;
     char line[302];
@@ -105,7 +105,7 @@ static void pj_gc_sortcatalog( projCtx ctx, PJ_GridCatalog *catalog )
 /*      token count.                                                    */
 /************************************************************************/
 
-static int pj_gc_read_csv_line( projCtx ctx, FILE *fp, 
+static int pj_gc_read_csv_line( projCtx ctx, PAFile fp, 
                                 char **tokens, int max_tokens ) 
 {
     char line[302];
@@ -180,7 +180,7 @@ double pj_gc_parsedate( projCtx ctx, const char *date_string )
 /*        gridname,ll_long,ll_lat,ur_long,ur_lat,priority,date          */
 /************************************************************************/
 
-static int pj_gc_readentry( projCtx ctx, FILE *fp, PJ_GridCatalogEntry *entry ) 
+static int pj_gc_readentry( projCtx ctx, PAFile fp, PJ_GridCatalogEntry *entry) 
 {
 #define MAX_TOKENS 30
     char *tokens[MAX_TOKENS];
diff --git a/src/pj_gridinfo.c b/src/pj_gridinfo.c
index a153dcf5..3ce7ecd3 100644
--- a/src/pj_gridinfo.c
+++ b/src/pj_gridinfo.c
@@ -126,7 +126,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
 /* -------------------------------------------------------------------- */
     if( strcmp(gi->format,"ctable") == 0 )
     {
-        FILE *fid;
+        PAFile fid;
         int result;
 
         fid = pj_open_lib( ctx, gi->filename, "rb" );
@@ -139,7 +139,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
 
         result = nad_ctable_load( ctx, gi->ct, fid );
 
-        fclose( fid );
+        pj_ctx_fclose( ctx, fid );
 
         return result;
     }
@@ -149,7 +149,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
 /* -------------------------------------------------------------------- */
     else if( strcmp(gi->format,"ctable2") == 0 )
     {
-        FILE *fid;
+        PAFile fid;
         int result;
 
         fid = pj_open_lib( ctx, gi->filename, "rb" );
@@ -162,7 +162,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
 
         result = nad_ctable2_load( ctx, gi->ct, fid );
 
-        fclose( fid );
+        pj_ctx_fclose( ctx, fid );
 
         return result;
     }
@@ -178,7 +178,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
     {
         double	*row_buf;
         int	row;
-        FILE *fid;
+        PAFile fid;
 
         fid = pj_open_lib( ctx, gi->filename, "rb" );
         
@@ -188,7 +188,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
             return 0;
         }
 
-        fseek( fid, gi->grid_offset, SEEK_SET );
+        pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
 
         row_buf = (double *) pj_malloc(gi->ct->lim.lam * sizeof(double) * 2);
         gi->ct->cvs = (FLP *) pj_malloc(gi->ct->lim.lam*gi->ct->lim.phi*sizeof(FLP));
@@ -204,7 +204,8 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
             FLP     *cvs;
             double  *diff_seconds;
 
-            if( fread( row_buf, sizeof(double), gi->ct->lim.lam * 2, fid ) 
+            if( pj_ctx_fread( ctx, row_buf, 
+                              sizeof(double), gi->ct->lim.lam * 2, fid ) 
                 != 2 * gi->ct->lim.lam )
             {
                 pj_dalloc( row_buf );
@@ -231,7 +232,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
 
         pj_dalloc( row_buf );
 
-        fclose( fid );
+        pj_ctx_fclose( ctx, fid );
 
         return 1;
     }
@@ -247,7 +248,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
     {
         float	*row_buf;
         int	row;
-        FILE *fid;
+        PAFile fid;
 
         pj_log( ctx, PJ_LOG_DEBUG_MINOR, 
                 "NTv2 - loading grid %s", gi->ct->id );
@@ -260,7 +261,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
             return 0;
         }
 
-        fseek( fid, gi->grid_offset, SEEK_SET );
+        pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
 
         row_buf = (float *) pj_malloc(gi->ct->lim.lam * sizeof(float) * 4);
         gi->ct->cvs = (FLP *) pj_malloc(gi->ct->lim.lam*gi->ct->lim.phi*sizeof(FLP));
@@ -276,7 +277,8 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
             FLP     *cvs;
             float   *diff_seconds;
 
-            if( fread( row_buf, sizeof(float), gi->ct->lim.lam*4, fid ) 
+            if( pj_ctx_fread( ctx, row_buf, sizeof(float), 
+                              gi->ct->lim.lam*4, fid ) 
                 != 4 * gi->ct->lim.lam )
             {
                 pj_dalloc( row_buf );
@@ -305,8 +307,8 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
         }
 
         pj_dalloc( row_buf );
-
-        fclose( fid );
+        
+        pj_ctx_fclose( ctx, fid );
 
         return 1;
     }
@@ -317,7 +319,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
     else if( strcmp(gi->format,"gtx") == 0 )
     {
         int   words = gi->ct->lim.lam * gi->ct->lim.phi;
-        FILE *fid;
+        PAFile fid;
 
         fid = pj_open_lib( ctx, gi->filename, "rb" );
         
@@ -327,7 +329,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
             return 0;
         }
 
-        fseek( fid, gi->grid_offset, SEEK_SET );
+        pj_ctx_fseek( ctx, fid, gi->grid_offset, SEEK_SET );
 
         gi->ct->cvs = (FLP *) pj_malloc(words*sizeof(float));
         if( gi->ct->cvs == NULL )
@@ -336,7 +338,8 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
             return 0;
         }
         
-        if( fread( gi->ct->cvs, sizeof(float), words, fid ) != words )
+        if( pj_ctx_fread( ctx, gi->ct->cvs, sizeof(float), words, fid ) 
+            != words )
         {
             pj_dalloc( gi->ct->cvs );
             gi->ct->cvs = NULL;
@@ -346,7 +349,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
         if( IS_LSB )
             swap_words( (unsigned char *) gi->ct->cvs, 4, words );
 
-        fclose( fid );
+        pj_ctx_fclose( ctx, fid );
         return 1;
     }
 
@@ -362,7 +365,7 @@ int pj_gridinfo_load( projCtx ctx, PJ_GRIDINFO *gi )
 /*      Load a ntv2 (.gsb) file.                                        */
 /************************************************************************/
 
-static int pj_gridinfo_init_ntv2( projCtx ctx, FILE *fid, PJ_GRIDINFO *gilist )
+static int pj_gridinfo_init_ntv2( projCtx ctx, PAFile fid, PJ_GRIDINFO *gilist )
 
 {
     unsigned char header[11*16];
@@ -381,7 +384,7 @@ static int pj_gridinfo_init_ntv2( projCtx ctx, FILE *fid, PJ_GRIDINFO *gilist )
 /* -------------------------------------------------------------------- */
 /*      Read the overview header.                                       */
 /* -------------------------------------------------------------------- */
-    if( fread( header, sizeof(header), 1, fid ) != 1 )
+    if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
     {
         pj_ctx_set_errno( ctx, -38 );
         return 0;
@@ -419,7 +422,7 @@ static int pj_gridinfo_init_ntv2( projCtx ctx, FILE *fid, PJ_GRIDINFO *gilist )
 /* -------------------------------------------------------------------- */
 /*      Read header.                                                    */
 /* -------------------------------------------------------------------- */
-        if( fread( header, sizeof(header), 1, fid ) != 1 )
+        if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
         {
             pj_ctx_set_errno( ctx, -38 );
             return 0;
@@ -507,7 +510,7 @@ static int pj_gridinfo_init_ntv2( projCtx ctx, FILE *fid, PJ_GRIDINFO *gilist )
 
         gi->ct = ct;
         gi->format = "ntv2";
-        gi->grid_offset = ftell( fid );
+        gi->grid_offset = pj_ctx_ftell( ctx, fid );
 
 /* -------------------------------------------------------------------- */
 /*      Attach to the correct list or sublist.                          */
@@ -556,7 +559,7 @@ static int pj_gridinfo_init_ntv2( projCtx ctx, FILE *fid, PJ_GRIDINFO *gilist )
 /* -------------------------------------------------------------------- */
 /*      Seek past the data.                                             */
 /* -------------------------------------------------------------------- */
-        fseek( fid, gs_count * 16, SEEK_CUR );
+        pj_ctx_fseek( ctx, fid, gs_count * 16, SEEK_CUR );
     }
 
     return 1;
@@ -568,7 +571,7 @@ static int pj_gridinfo_init_ntv2( projCtx ctx, FILE *fid, PJ_GRIDINFO *gilist )
 /*      Load an NTv1 style Canadian grid shift file.                    */
 /************************************************************************/
 
-static int pj_gridinfo_init_ntv1( projCtx ctx, FILE * fid, PJ_GRIDINFO *gi )
+static int pj_gridinfo_init_ntv1( projCtx ctx, PAFile fid, PJ_GRIDINFO *gi )
 
 {
     unsigned char header[176];
@@ -588,7 +591,7 @@ static int pj_gridinfo_init_ntv1( projCtx ctx, FILE * fid, PJ_GRIDINFO *gi )
 /* -------------------------------------------------------------------- */
 /*      Read the header.                                                */
 /* -------------------------------------------------------------------- */
-    if( fread( header, sizeof(header), 1, fid ) != 1 )
+    if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
     {
         pj_ctx_set_errno( ctx, -38 );
         return 0;
@@ -643,7 +646,7 @@ static int pj_gridinfo_init_ntv1( projCtx ctx, FILE * fid, PJ_GRIDINFO *gi )
     ct->cvs = NULL;
 
     gi->ct = ct;
-    gi->grid_offset = ftell( fid );
+    gi->grid_offset = pj_ctx_ftell( ctx, fid );
     gi->format = "ntv1";
 
     return 1;
@@ -655,7 +658,7 @@ static int pj_gridinfo_init_ntv1( projCtx ctx, FILE * fid, PJ_GRIDINFO *gi )
 /*      Load a NOAA .gtx vertical datum shift file.                     */
 /************************************************************************/
 
-static int pj_gridinfo_init_gtx( projCtx ctx, FILE * fid, PJ_GRIDINFO *gi )
+static int pj_gridinfo_init_gtx( projCtx ctx, PAFile fid, PJ_GRIDINFO *gi )
 
 {
     unsigned char header[40];
@@ -676,7 +679,7 @@ static int pj_gridinfo_init_gtx( projCtx ctx, FILE * fid, PJ_GRIDINFO *gi )
 /* -------------------------------------------------------------------- */
 /*      Read the header.                                                */
 /* -------------------------------------------------------------------- */
-    if( fread( header, sizeof(header), 1, fid ) != 1 )
+    if( pj_ctx_fread( ctx, header, sizeof(header), 1, fid ) != 1 )
     {
         pj_ctx_set_errno( ctx, -38 );
         return 0;
@@ -766,7 +769,7 @@ PJ_GRIDINFO *pj_gridinfo_init( projCtx ctx, const char *gridname )
 {
     char 	fname[MAX_PATH_FILENAME+1];
     PJ_GRIDINFO *gilist;
-    FILE 	*fp;
+    PAFile 	fp;
     char	header[160];
 
     errno = pj_errno = 0;
@@ -800,14 +803,14 @@ PJ_GRIDINFO *pj_gridinfo_init( projCtx ctx, const char *gridname )
 /* -------------------------------------------------------------------- */
 /*      Load a header, to determine the file type.                      */
 /* -------------------------------------------------------------------- */
-    if( fread( header, sizeof(header), 1, fp ) != 1 )
+    if( pj_ctx_fread( ctx, header, sizeof(header), 1, fp ) != 1 )
     {
-        fclose( fp );
+        pj_ctx_fclose( ctx, fp );
         pj_ctx_set_errno( ctx, -38 );
         return gilist;
     }
 
-    fseek( fp, SEEK_SET, 0 );
+    pj_ctx_fseek( ctx, fp, SEEK_SET, 0 );
 
 /* -------------------------------------------------------------------- */
 /*      Determine file type.                                            */
@@ -864,7 +867,7 @@ PJ_GRIDINFO *pj_gridinfo_init( projCtx ctx, const char *gridname )
                 (ct->ll.phi + (ct->lim.phi-1)*ct->del.phi) * RAD_TO_DEG );
     }
 
-    fclose(fp);
+    pj_ctx_fclose(ctx, fp);
 
     return gilist;
 }
diff --git a/src/pj_init.c b/src/pj_init.c
index bc8691f4..fef2b5ff 100644
--- a/src/pj_init.c
+++ b/src/pj_init.c
@@ -35,48 +35,181 @@
 #include <string.h>
 #include <errno.h>
 #include <locale.h>
+#include <ctype.h>
 
 PJ_CVSID("$Id$");
 
+typedef struct {
+    projCtx ctx;
+    PAFile fid;
+    char buffer[8193];
+    int buffer_filled;
+    int at_eof;
+} pj_read_state;
+
+/************************************************************************/
+/*                            fill_buffer()                             */
+/************************************************************************/
+
+static const char *fill_buffer(pj_read_state *state, const char *last_char)
+{
+    size_t bytes_read;
+    int char_remaining, char_requested;
+
+/* -------------------------------------------------------------------- */
+/*      Don't bother trying to read more if we are at eof, or if the    */
+/*      buffer is still over half full.                                 */
+/* -------------------------------------------------------------------- */
+    if (last_char == NULL)
+        last_char = state->buffer;
+
+    if (state->at_eof)
+        return last_char;
+
+    char_remaining = state->buffer_filled - (last_char - state->buffer);
+    if (char_remaining >= sizeof(state->buffer) / 2)
+        return last_char;
+
+/* -------------------------------------------------------------------- */
+/*      Move the existing data to the start of the buffer.              */
+/* -------------------------------------------------------------------- */
+    memmove(state->buffer, last_char, char_remaining);
+    state->buffer_filled = char_remaining;
+    last_char = state->buffer;
+
+/* -------------------------------------------------------------------- */
+/*      Refill.                                                         */
+/* -------------------------------------------------------------------- */
+    char_requested = sizeof(state->buffer) - state->buffer_filled - 1;
+    bytes_read = pj_ctx_fread( state->ctx, state->buffer + state->buffer_filled,
+                               1, char_requested, state->fid );
+    if (bytes_read < char_requested)
+    {
+        state->at_eof = 1;
+        state->buffer[state->buffer_filled + bytes_read] = '\0';
+    }
+
+    state->buffer_filled += bytes_read;
+    return last_char;
+}
+
 /************************************************************************/
 /*                              get_opt()                               */
 /************************************************************************/
 static paralist *
-get_opt(projCtx ctx, paralist **start, FILE *fid, char *name, paralist *next) {
-    char sword[302], *word = sword+1;
-    int first = 1, len, c;
+get_opt(projCtx ctx, paralist **start, PAFile fid, char *name, paralist *next) {
+    pj_read_state *state = (pj_read_state*) calloc(1,sizeof(pj_read_state));
+    char sword[302];
+    int len;
+    int in_target = 0;
+    const char *next_char = NULL;
+
+    state->fid = fid;
+    state->ctx = ctx;
+    next_char = fill_buffer(state, NULL);
 
     len = strlen(name);
     *sword = 't';
-    while (fscanf(fid, "%300s", word) == 1) {
-        if (*word == '#') /* skip comments */
-            while((c = fgetc(fid)) != EOF && c != '\n') ;
-        else if (*word == '<') { /* control name */
-            if (first && !strncmp(name, word + 1, len)
-                && word[len + 1] == '>')
-                first = 0;
-            else if (!first && *word == '<') {
-                while((c = fgetc(fid)) != EOF && c != '\n') ;
+
+    /* loop till we find our target keyword */
+    while (*next_char) 
+    {
+        next_char = fill_buffer(state, next_char);
+
+        /* Skip white space. */
+        while( isspace(*next_char) )
+            next_char++;
+
+        next_char = fill_buffer(state, next_char);
+        
+        /* for comments, skip past end of line. */
+        if( *next_char == '#' ) 
+        {
+            while( *next_char && *next_char != '\n' )
+                next_char++;
+
+            next_char = fill_buffer(state, next_char);
+            if (*next_char == '\n')
+                next_char++;
+            if (*next_char == '\r')
+                next_char++;
+            
+        } 
+
+        /* Is this our target? */
+        else if( *next_char == '<' ) 
+        {
+            /* terminate processing target on the next block definition */
+            if (in_target)
                 break;
+
+            next_char++;
+            if (strncmp(name, next_char, len) == 0
+                && next_char[len] == '>') 
+            {
+                /* skip past target word */
+                next_char += len + 1;
+                in_target = 1;
             }
-        } else if (!first && !pj_param(ctx, *start, sword).i) {
-            /* don't default ellipse if datum, ellps or any earth model
-               information is set. */
-            if( strncmp(word,"ellps=",6) != 0 
-                || (!pj_param(ctx, *start, "tdatum").i 
-                    && !pj_param(ctx, *start, "tellps").i 
-                    && !pj_param(ctx, *start, "ta").i 
-                    && !pj_param(ctx, *start, "tb").i 
-                    && !pj_param(ctx, *start, "trf").i 
-                    && !pj_param(ctx, *start, "tf").i) )
+            else 
             {
-                next = next->next = pj_mkparam(word);
+                /* skip past end of line */
+                while( *next_char && *next_char != '\n' )
+                    next_char++;
             }
         }
-    }
+        else if (in_target) 
+        {
+            const char *start_of_word = next_char;
+            int word_len = 0;
+
+            if (*start_of_word == '+')
+            {
+                start_of_word++;
+                next_char++;
+            }
+
+            /* capture parameter */
+            while( *next_char && !isspace(*next_char) )
+            {
+                next_char++;
+                word_len++;
+            }
+
+            strncpy(sword+1, start_of_word, word_len);
+            sword[word_len+1] = '\0';
+
+            /* do not override existing parameter value of same name */
+            if (!pj_param(ctx, *start, sword).i) {
+                /* don't default ellipse if datum, ellps or any earth model
+                   information is set. */
+                if( strncmp(sword+1,"ellps=",6) != 0 
+                    || (!pj_param(ctx, *start, "tdatum").i 
+                        && !pj_param(ctx, *start, "tellps").i 
+                        && !pj_param(ctx, *start, "ta").i 
+                        && !pj_param(ctx, *start, "tb").i 
+                        && !pj_param(ctx, *start, "trf").i 
+                        && !pj_param(ctx, *start, "tf").i) )
+                {
+                    next = next->next = pj_mkparam(sword+1);
+                }
+            }
+            
+        }
+        else 
+        {
+            /* skip past word */
+            while( *next_char && !isspace(*next_char) )
+                next_char++;
+            
+        }
+    }        
 
     if (errno == 25)
         errno = 0;
+
+    free(state);
+
     return next;
 }
 
@@ -85,13 +218,13 @@ get_opt(projCtx ctx, paralist **start, FILE *fid, char *name, paralist *next) {
 /************************************************************************/
 static paralist *
 get_defaults(projCtx ctx, paralist **start, paralist *next, char *name) {
-    FILE *fid;
+    PAFile fid;
 
     if ( (fid = pj_open_lib(ctx,"proj_def.dat", "rt")) != NULL) {
         next = get_opt(ctx, start, fid, "general", next);
-        rewind(fid);
+        pj_ctx_fseek(ctx, fid, 0, SEEK_SET);
         next = get_opt(ctx, start, fid, name, next);
-        (void)fclose(fid);
+        pj_ctx_fclose(ctx, fid);
     }
     if (errno)
         errno = 0; /* don't care if can't open file */
@@ -106,7 +239,7 @@ get_defaults(projCtx ctx, paralist **start, paralist *next, char *name) {
 static paralist *
 get_init(projCtx ctx, paralist **start, paralist *next, char *name) {
     char fname[MAX_PATH_FILENAME+ID_TAG_MAX+3], *opt;
-    FILE *fid;
+    PAFile fid;
     paralist *init_items = NULL;
     const paralist *orig_next = next;
 
@@ -136,7 +269,7 @@ get_init(projCtx ctx, paralist **start, paralist *next, char *name) {
         next = get_opt(ctx, start, fid, opt, next);
     else
         return NULL;
-    (void)fclose(fid);
+    pj_ctx_fclose(ctx, fid);
     if (errno == 25)
         errno = 0; /* unknown problem with some sys errno<-25 */
 
diff --git a/src/pj_open_lib.c b/src/pj_open_lib.c
index bc8c98ac..0a11dab4 100644
--- a/src/pj_open_lib.c
+++ b/src/pj_open_lib.c
@@ -98,11 +98,11 @@ void pj_set_searchpath ( int count, const char **path )
 /*                            pj_open_lib()                             */
 /************************************************************************/
 
-FILE *
+PAFile
 pj_open_lib(projCtx ctx, char *name, char *mode) {
     char fname[MAX_PATH_FILENAME+1];
     const char *sysname;
-    FILE *fid;
+    PAFile fid;
     int n = 0;
     int i;
 #ifdef WIN32
@@ -145,7 +145,7 @@ pj_open_lib(projCtx ctx, char *name, char *mode) {
     } else /* just try it bare bones */
         sysname = name;
 
-    if ((fid = fopen(sysname, mode)) != NULL)
+    if ((fid = pj_ctx_fopen(ctx, sysname, mode)) != NULL)
         errno = 0;
 
     /* If none of those work and we have a search path, try it */
@@ -155,7 +155,7 @@ pj_open_lib(projCtx ctx, char *name, char *mode) {
         {
             sprintf(fname, "%s%c%s", search_path[i], DIR_CHAR, name);
             sysname = fname;
-            fid = fopen (sysname, mode);
+            fid = pj_ctx_fopen(ctx, sysname, mode);
         }
         if (fid)
             errno = 0;
diff --git a/src/projects.h b/src/projects.h
index fc64ba59..0e24566e 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -431,7 +431,7 @@ double *pj_authset(double);
 double pj_authlat(double, double *);
 COMPLEX pj_zpoly1(COMPLEX, COMPLEX *, int);
 COMPLEX pj_zpolyd1(COMPLEX, COMPLEX *, int, COMPLEX *);
-FILE *pj_open_lib(projCtx, char *, char *);
+PAFile pj_open_lib(projCtx, char *, char *);
 
 int pj_deriv(LP, double, PJ *, struct DERIVS *);
 int pj_factors(LP, PJ *, double, struct FACTORS *);
@@ -462,10 +462,10 @@ int bch2bps(projUV, projUV, projUV **, int, int);
 LP nad_intr(LP, struct CTABLE *);
 LP nad_cvt(LP, int, struct CTABLE *);
 struct CTABLE *nad_init(projCtx ctx, char *);
-struct CTABLE *nad_ctable_init( projCtx ctx, FILE * fid );
-int nad_ctable_load( projCtx ctx, struct CTABLE *, FILE * fid );
-struct CTABLE *nad_ctable2_init( projCtx ctx, FILE * fid );
-int nad_ctable2_load( projCtx ctx, struct CTABLE *, FILE * fid );
+struct CTABLE *nad_ctable_init( projCtx ctx, PAFile fid );
+int nad_ctable_load( projCtx ctx, struct CTABLE *, PAFile fid );
+struct CTABLE *nad_ctable2_init( projCtx ctx, PAFile fid );
+int nad_ctable2_load( projCtx ctx, struct CTABLE *, PAFile fid );
 void nad_free(struct CTABLE *);
 
 /* higher level handling of datum grid shift files */