SCP: Extend TYPE/CAT command to support offset and line count limit

scp.c

@@ -1235,9 +1235,21 @@ static const char simh_help1[] =
 #define HLP_TYPE         "*Commands Displaying_Files TYPE"
       "3TYPE\n"
       "++TYPE file                 display a file contents\n"
+      "4Switches\n"
+      " The -O switch start displaying file contents at the specified\n"
+      " file offset.\n\n"
+      " The -N switch will display up to a specified number of lines\n"
+      " from the file.\n\n"
+      "++TYPE -{O}{N} {offset} {lines} file\n\n"
 #define HLP_CAT          "*Commands Displaying_Files CAT"
       "3CAT\n"
       "++CAT file                  display a file contents\n"
+      "4Switches\n"
+      " The -O switch start displaying file contents at the specified\n"
+      " file offset.\n\n"
+      " The -N switch will display up to a specified number of lines\n"
+      " from the file.\n\n"
+      "++TYPE -{O}{N} {offset} {lines} file\n\n"
       "2Removing Files\n"
 #define HLP_DELETE       "*Commands Removing_Files DEL"
       "3DELETE\n"
@@ -6877,6 +6889,8 @@ if (r != SCPE_OK) {
 return r;
 }
 
+static long sim_type_file_offset;
+static long sim_type_line_count;
 
 typedef struct {
     t_stat stat;
@@ -6890,6 +6904,7 @@ static void sim_type_entry (const char *directory,
 {
 char FullPath[PATH_MAX + 1];
 FILE *file;
+long lines = 0;
 char lbuf[4*CBUFSIZE];
 
 sprintf (FullPath, "%s%s", directory, filename);
@@ -6899,7 +6914,10 @@ if (file == NULL)                           /* open failed? */
     return;
 sim_printf ("\n%s\n\n", FullPath);
 lbuf[sizeof(lbuf)-1] = '\0';
-while (fgets (lbuf, sizeof(lbuf)-1, file))
+if (sim_type_file_offset)
+    (void)fseek (file, sim_type_file_offset, SEEK_SET);
+while ((NULL != fgets (lbuf, sizeof(lbuf)-1, file)) && 
+       (lines++ < sim_type_line_count))
     sim_printf ("%s", lbuf);
 fclose (file);
 }
@@ -6908,11 +6926,36 @@ fclose (file);
 t_stat type_cmd (int32 flg, CONST char *cptr)
 {
 FILE *file;
+long lines = 0;
 char lbuf[4*CBUFSIZE];
 
+sim_type_file_offset = 0;                           /* beginning of file */
+sim_type_line_count = 0X7FFFFFFF;                   /* output many lines */
 GET_SWITCHES (cptr);                                    /* get switches */
 if ((!cptr) || (*cptr == 0))
     return SCPE_2FARG;
+if (sim_switches & SWMASK ('O')) {      /* Specify Offset in file */
+    char gbuf[CBUFSIZE];
+    char *eptr;
+
+    cptr = get_glyph (cptr, gbuf, 0);
+    if ((!cptr) || (*cptr == 0))
+        return SCPE_2FARG;
+    sim_type_file_offset = strtol (gbuf, &eptr, 0);
+    if ((*eptr) || (sim_type_file_offset < 0))
+        return sim_messagef (SCPE_ARG, "Invalid file offset: %s\n", gbuf);
+    }
+if (sim_switches & SWMASK ('N')) {      /* Specify Line Count to display */
+    char gbuf[CBUFSIZE];
+    char *eptr;
+
+    cptr = get_glyph (cptr, gbuf, 0);
+    if ((!cptr) || (*cptr == 0))
+        return SCPE_2FARG;
+    sim_type_line_count = strtol (gbuf, &eptr, 0);
+    if ((*eptr) || (sim_type_line_count < 0))
+        return sim_messagef (SCPE_ARG, "Invalid file line count: %s\n", gbuf);
+    }
 lbuf[sizeof(lbuf)-1] = '\0';
 strlcpy (lbuf, cptr, sizeof(lbuf));
 sim_trim_endspc(lbuf);
@@ -6928,7 +6971,10 @@ if (file == NULL) {                         /* open failed? */
     return sim_messagef (SCPE_OPENERR, "The system cannot find the file specified.\n");
     }
 lbuf[sizeof(lbuf)-1] = '\0';
-while (fgets (lbuf, sizeof(lbuf)-1, file))
+if (sim_type_file_offset)
+    (void)fseek (file, sim_type_file_offset, SEEK_SET);
+while ((NULL != fgets (lbuf, sizeof(lbuf)-1, file)) && 
+       (lines++ < sim_type_line_count))
     sim_printf ("%s", lbuf);
 fclose (file);
 return SCPE_OK;