LXR toybox/lib/utf8.c

   1#include "toys.h"
   2
   3// Show width many columns, negative means from right edge, out=0 just measure
   4// if escout, send it unprintable chars, otherwise pass through raw data.
   5// Returns width in columns, moves *str to end of data consumed.
   6int crunch_str(char **str, int width, FILE *out, char *escmore,
   7  int (*escout)(FILE *out, int cols, int wc))
   8{
   9  int columns = 0, col, bytes;
  10  char *start, *end;
  11  unsigned wc;
  12
  13  for (end = start = *str; *end; columns += col, end += bytes) {
  14    if ((bytes = utf8towc(&wc, end, 4))>0 && (col = wcwidth(wc))>=0) {
  15      if (!escmore || wc>255 || !strchr(escmore, wc)) {
  16        if (width-columns<col) break;
  17        if (out) fwrite(end, bytes, 1, out);
  18
  19        continue;
  20      }
  21    }
  22
  23    if (bytes<1) {
  24      bytes = 1;
  25      wc = *end;
  26    }
  27    col = width-columns;
  28    if (col<1) break;
  29    if (escout) {
  30      if ((col = escout(out, col, wc))<0) break;
  31    } else if (out) fwrite(end, 1, bytes, out);
  32  }
  33  *str = end;
  34
  35  return columns;
  36}
  37
  38
  39// standard escapes: ^X if <32, <XX> if invalid UTF8, U+XXXX if UTF8 !iswprint()
  40int crunch_escape(FILE *out, int cols, int wc)
  41{
  42  char buf[11];
  43  int rc;
  44
  45  if (wc<' ') rc = sprintf(buf, "^%c", '@'+wc);
  46  else if (wc<256) rc = sprintf(buf, "<%02X>", wc);
  47  else rc = sprintf(buf, "U+%04X", wc);
  48
  49  if (rc > cols) buf[rc = cols] = 0;
  50  if (out) fputs(buf, out);
  51
  52  return rc;
  53}
  54
  55// Display "standard" escapes in reverse video.
  56int crunch_rev_escape(FILE *out, int cols, int wc)
  57{
  58  int rc;
  59
  60  xputsn("\e[7m");
  61  rc = crunch_escape(out, cols, wc);
  62  xputsn("\e[27m");
  63
  64  return rc;
  65}
  66
  67// Write width chars at start of string to strdout with standard escapes
  68// Returns length in columns so caller can pad it out with spaces.
  69int draw_str(char *start, int width)
  70{
  71  return crunch_str(&start, width, stdout, 0, crunch_rev_escape);
  72}
  73
  74// Return utf8 columns
  75int utf8len(char *str)
  76{
  77  return crunch_str(&str, INT_MAX, 0, 0, crunch_rev_escape);
  78}
  79
  80// Return bytes used by (up to) this many columns
  81int utf8skip(char *str, int width)
  82{
  83  char *s = str;
  84
  85  crunch_str(&s, width, 0, 0, crunch_rev_escape);
  86
  87  return s-str;
  88}
  89
  90// Print utf8 to stdout with standard escapes, trimmed to width and padded
  91// out to padto. If padto<0 left justify. Returns columns printed
  92int draw_trim_esc(char *str, int padto, int width, char *escmore,
  93  int (*escout)(FILE *out, int cols, int wc))
  94{
  95  int apad = abs(padto), len = utf8len(str);
  96
  97  if (padto>=0 && len>width) str += utf8skip(str, len-width);
  98  if (len>width) len = width;
  99
 100  // Left pad if right justified 
 101  if (padto>0 && apad>len) printf("%*s", apad-len, "");
 102  crunch_str(&str, len, stdout, 0, crunch_rev_escape);
 103  if (padto<0 && apad>len) printf("%*s", apad-len, "");
 104
 105  return (apad > len) ? apad : len;
 106}
 107
 108// draw_trim_esc() with default escape
 109int draw_trim(char *str, int padto, int width)
 110{
 111  return draw_trim_esc(str, padto, width, 0, 0);
 112}
 113