/src/util-linux/include/carefulputc.h

Source
#ifndef UTIL_LINUX_CAREFULPUTC_H
#define UTIL_LINUX_CAREFULPUTC_H

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdbool.h>

#include "widechar.h"
#include "cctype.h"

/*
 * A puts() for use in write and wall (that sometimes are sgid tty).
 * It avoids control and invalid characters.
 * The locale of the recipient is nominally unknown,
 * but it's a solid bet that it's compatible with the author's.
 * Use soft_width=0 to disable wrapping.
 */
static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf, int soft_width)
{
  int ret = 0, col = 0;

  for (size_t slen = strlen(s); *s; ++s, --slen) {
    if (*s == '\t')
      col += (7 - (col % 8)) - 1;
    else if (*s == '\r')
      col = -1;
    else if (*s == '\a')
      --col;

    if ((soft_width && col >= soft_width) || *s == '\n') {
      if (soft_width) {
        fprintf(fp, "%*s", soft_width - col, "");
        col = 0;
      }
      ret = fputs(cr_lf ? "\r\n" : "\n", fp);
      if (*s == '\n' || ret < 0)
        goto wrote;
    }

    if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r') {
      ret = putc(*s, fp);
      ++col;
    } else if (!c_isascii(*s)) {
#ifdef HAVE_WIDECHAR
      wchar_t w;
      size_t clen = mbtowc(&w, s, slen);
      switch(clen) {
        case (size_t)-2:  // incomplete
        case (size_t)-1:  // EILSEQ
          mbtowc(NULL, NULL, 0);
        nonprint:
          col += ret = fprintf(fp, "\\%3hho", *s);
          break;
        default:
          if(!iswprint(w))
            goto nonprint;
          ret = fwrite(s, 1, clen, fp);
          if (soft_width)
            col += wcwidth(w);
          s += clen - 1;
          slen -= clen - 1;
          break;
      }
#else
      col += ret = fprintf(fp, "\\%3hho", *s);
#endif
    } else {
      ret = fputs((char[]){ ctrl, *s ^ 0x40, '\0' }, fp);
      col += 2;
    }

  wrote:
    if (ret < 0)
      return EOF;
  }
  return 0;
}

static inline void fputs_quoted_case(const char *data, FILE *out, int dir)
{
  const char *p;

  fputc('"', out);
  for (p = data; p && *p; p++) {
    if ((unsigned char) *p == 0x22 ||   /* " */
        (unsigned char) *p == 0x5c ||   /* \ */
        (unsigned char) *p == 0x60 ||   /* ` */
        (unsigned char) *p == 0x24 ||   /* $ */
        !isprint((unsigned char) *p) ||
        iscntrl((unsigned char) *p)) {

      fprintf(out, "\\x%02x", (unsigned char) *p);
    } else
      fputc(dir ==  1 ? toupper(*p) :
            dir == -1 ? tolower(*p) :
            *p, out);
  }
  fputc('"', out);
}

#define fputs_quoted(_d, _o)    fputs_quoted_case(_d, _o, 0)
#define fputs_quoted_upper(_d, _o)  fputs_quoted_case(_d, _o, 1)
#define fputs_quoted_lower(_d, _o)  fputs_quoted_case(_d, _o, -1)

static inline void fputs_nonblank(const char *data, FILE *out)
{
  const char *p;

  for (p = data; p && *p; p++) {
    if (isblank((unsigned char) *p) ||
        (unsigned char) *p == 0x5c ||   /* \ */
        !isprint((unsigned char) *p) ||
        iscntrl((unsigned char) *p)) {

      fprintf(out, "\\x%02x", (unsigned char) *p);

    } else
      fputc(*p, out);
  }
}

#endif  /*  _CAREFULPUTC_H  */

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Created: 2025-11-16 06:06