cct: forward comments to output

Any text written after the coordinate input will automatically be
forwarded to the output stream. Text in columns before the coordinate
input is discarded in the output. This works for any combination of -c, -t
and -z parameters:

$ echo 12 56 100 2018.0 comment comment | cct +proj=merc
 1335833.8895   7522963.2411      100.0000     2018.0000 comment commen

$ echo text 12 56 100 2018.0 comment | cct -c 2,3,4,5 +proj=merc
 1335833.8895   7522963.2411      100.0000     2018.0000 comment

$ echo text 12 56 comment | cct -c 2,3 -t0 -z0 +proj=merc
 1335833.8895   7522963.2411        0.0000        0.0000 comment

$ echo 12 56 comment | cct -t0 -z0 +proj=merc
 1335833.8895   7522963.2411        0.0000        0.0000 comment

Closes #918

1 files changed, 34 insertions, 5 deletions

diff --git a/src/cct.c b/src/cct.c
index 7a53beeb..7d02eaac 100644
--- a/src/cct.c
+++ b/src/cct.c
@@ -206,8 +206,12 @@ int main(int argc, char **argv) {
     PJ_COORD point;
     PJ_PROJ_INFO info;
     OPTARGS *o;
+    char blank_comment[] = "";
+    char whitespace[] = " ";
+    char *comment;
+    char *comment_delimiter;
     char *buf;
-    int nfields = 4, direction = 1, skip_lines = 0, verbose;
+    int i, nfields = 4, direction = 1, skip_lines = 0, verbose;
     double fixed_z = HUGE_VAL, fixed_time = HUGE_VAL;
     int decimals_angles = 10;
     int decimals_distances = 4;
@@ -268,7 +272,6 @@ int main(int argc, char **argv) {
         int dec = atoi (opt_arg (o, "d"));
         decimals_angles = dec;
         decimals_distances = dec;
-        nfields--;
     }
 
     if (opt_given (o, "s")) {
@@ -276,8 +279,13 @@ int main(int argc, char **argv) {
     }
 
     if (opt_given (o, "c")) {
+        int ncols;
+        /* reset colum numbers to ease comment output later on */
+        for (i=0; i<4; i++)
+            columns_xyzt[i] = 0;
+
         /* cppcheck-suppress invalidscanf */
-        int ncols = sscanf (opt_arg (o, "c"), "%d,%d,%d,%d", columns_xyzt, columns_xyzt+1, columns_xyzt+2, columns_xyzt+3);
+        ncols = sscanf (opt_arg (o, "c"), "%d,%d,%d,%d", columns_xyzt, columns_xyzt+1, columns_xyzt+2, columns_xyzt+3);
         if (ncols != nfields) {
             print (PJ_LOG_ERROR, "%s: Too few input columns given: '%s'\n", o->progname, opt_arg (o, "c"));
             free (o);
@@ -371,14 +379,35 @@ int main(int argc, char **argv) {
         }
         proj_errno_restore (P, err);
 
+        /* handle comment string */
+        comment = column(buf, nfields+1);
+        if (opt_given(o, "c")) {
+            /* what number is the last coordinate column in the input data? */
+            int colmax = 0;
+            for (i=0; i<4; i++)
+                colmax = MAX(colmax, columns_xyzt[i]);
+            comment = column(buf, colmax+1);
+        }
+        comment_delimiter = (comment && *comment) ? whitespace : blank_comment;
+
         /* Time to print the result */
         if (proj_angular_output (P, direction)) {
             point.lpzt.lam = proj_todeg (point.lpzt.lam);
             point.lpzt.phi = proj_todeg (point.lpzt.phi);
-            print (PJ_LOG_NONE, "%14.*f  %14.*f  %12.*f  %12.4f\n", decimals_angles, point.xyzt.x, decimals_angles, point.xyzt.y, decimals_distances, point.xyzt.z, point.xyzt.t);
+            print (PJ_LOG_NONE, "%14.*f  %14.*f  %12.*f  %12.4f%s%s\n",
+                   decimals_angles, point.xyzt.x,
+                   decimals_angles, point.xyzt.y,
+                   decimals_distances, point.xyzt.z,
+                   point.xyzt.t, comment_delimiter, comment
+            );
         }
         else
-            print (PJ_LOG_NONE, "%13.*f  %13.*f  %12.*f  %12.4f\n", decimals_distances, point.xyzt.x, decimals_distances, point.xyzt.y, decimals_distances, point.xyzt.z, point.xyzt.t);
+            print (PJ_LOG_NONE, "%13.*f  %13.*f  %12.*f  %12.4f%s%s\n",
+                   decimals_distances, point.xyzt.x,
+                   decimals_distances, point.xyzt.y,
+                   decimals_distances, point.xyzt.z,
+                   point.xyzt.t, comment_delimiter, comment
+            );
     }
 
     if (stdout != fout)