CODEWITHSUNDEEP
cwhitespacencurses
Andreas Grapentin
Andreas Grapentin

Reputation: 5796

ncurses - mvwprintw generates whitespace

I have a ncurses project, where I use mvwprintw to print a long string to a window. 

mvwprintw(traceview_window_flatprofile, 1, 0, "%s", flatprofile_as_str());

the result looks like this:

  %       self    children             self    children
 time      time      time     calls    /call     /call  name
 39.86    886 µs       0 ns       32  27697 ns      0 ns  addr_translate [13]
 25.69    571 µs   1454 µs          1    571 µs   1454 µs  main [0]
  7.02    156 µs       0 ns        1    156 µs       0 ns  addr_fini [66]
  6.28    139 µs  55006 ns         1    139 µs  55006 ns  addr_init [2]
  3.83  85094 ns  21956 ns        2  42547 ns  10978 ns  flatprofile_snprintf [43]
  2.08  46150 ns      0 ns        1  46150 ns      0 ns  addr_read_symbol_table [3]

When I print the same string to stderr, using

fprintf(stderr, "%s\n", flatprofile_as_str());

the result looks like:

  %       self    children             self    children
 time      time      time     calls    /call     /call  name
 39.86    886 µs      0 ns       32  27697 ns      0 ns  addr_translate [13]
 25.69    571 µs   1454 µs        1    571 µs   1454 µs  main [0]
  7.02    156 µs      0 ns        1    156 µs      0 ns  addr_fini [66]
  6.28    139 µs  55006 ns        1    139 µs  55006 ns  addr_init [2]
  3.83  85094 ns  21956 ns        2  42547 ns  10978 ns  flatprofile_snprintf [43]
  2.08  46150 ns      0 ns        1  46150 ns      0 ns  addr_read_symbol_table [3]

Do you know what could cause this difference?

EDIT: in addition to the answer below, the following question solves a related issue.
How to make ncurses display UTF-8 chars correctly in C?

Upvotes: 0

Views: 459

Answers (1)

Simas
Simas

Reputation: 44158

The difference seems to be caused by the special character µ i am not quite sure how you can fix it but you will probably have to adjust your flatprofile_as_str() function.

I remember having a similar problem with special chars from utf-8 and i solved it by using this function to count not the bytes but the actual lenght of a string:

int strlen_utf8(char *s) { 
   int i = 0, j = 0;
   while (s[i]) {
     if ((s[i] & 0xc0) != 0x80) j++;
     i++;
   }
   return j;
}

Upvotes: 1

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