include/carefulputc.h

   1 #ifndef UTIL_LINUX_CAREFULPUTC_H
   2 #define UTIL_LINUX_CAREFULPUTC_H
   3
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <ctype.h>
   7 #include <stdbool.h>
   8
   9 #include "widechar.h"
  10 #include "cctype.h"
  11
  12 /*
  13  * A puts() for use in write and wall (that sometimes are sgid tty).
  14  * It avoids control and invalid characters.
  15  * The locale of the recipient is nominally unknown,
  16  * but it's a solid bet that it's compatible with the author's.
  17  * Use soft_width=0 to disable wrapping.
  18  */
  19 static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf, int soft_width)
  20 {
  21         int ret = 0, col = 0;
  22
  23         for (size_t slen = strlen(s); *s; ++s, --slen) {
  24                 if (*s == '\t')
  25                         col += (7 - (col % 8)) - 1;
  26                 else if (*s == '\r')
  27                         col = -1;
  28                 else if (*s == '\a')
  29                         --col;
  30
  31                 if ((soft_width && col >= soft_width) || *s == '\n') {
  32                         if (soft_width) {
  33                                 fprintf(fp, "%*s", soft_width - col, "");
  34                                 col = 0;
  35                         }
  36                         ret = fputs(cr_lf ? "\r\n" : "\n", fp);
  37                         if (*s == '\n' || ret < 0)
  38                                 goto wrote;
  39                 }
  40
  41                 if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r') {
  42                         ret = putc(*s, fp);
  43                         ++col;
  44                 } else if (!c_isascii(*s)) {
  45 #ifdef HAVE_WIDECHAR
  46                         wchar_t w;
  47                         size_t clen = mbtowc(&w, s, slen);
  48                         switch(clen) {
  49                                 case (size_t)-2:  // incomplete
  50                                 case (size_t)-1:  // EILSEQ
  51                                         mbtowc(NULL, NULL, 0);
  52                                 nonprint:
  53                                         col += ret = fprintf(fp, "\\%3hho", *s);
  54                                         break;
  55                                 default:
  56                                         if(!iswprint(w))
  57                                                 goto nonprint;
  58                                         ret = fwrite(s, 1, clen, fp);
  59                                         if (soft_width)
  60                                                 col += wcwidth(w);
  61                                         s += clen - 1;
  62                                         slen -= clen - 1;
  63                                         break;
  64                         }
  65 #else
  66                         col += ret = fprintf(fp, "\\%3hho", *s);
  67 #endif
  68                 } else {
  69                         ret = fputs((char[]){ ctrl, *s ^ 0x40, '\0' }, fp);
  70                         col += 2;
  71                 }
  72
  73         wrote:
  74                 if (ret < 0)
  75                         return EOF;
  76         }
  77         return 0;
  78 }
  79
  80 static inline void fputs_quoted_case(const char *data, FILE *out, int dir)
  81 {
  82         const char *p;
  83
  84         fputc('"', out);
  85         for (p = data; p && *p; p++) {
  86                 if ((unsigned char) *p == 0x22 ||               /* " */
  87                     (unsigned char) *p == 0x5c ||               /* \ */
  88                     (unsigned char) *p == 0x60 ||               /* ` */
  89                     (unsigned char) *p == 0x24 ||               /* $ */
  90                     !isprint((unsigned char) *p) ||
  91                     iscntrl((unsigned char) *p)) {
  92
  93                         fprintf(out, "\\x%02x", (unsigned char) *p);
  94                 } else
  95                         fputc(dir ==  1 ? toupper(*p) :
  96                               dir == -1 ? tolower(*p) :
  97                               *p, out);
  98         }
  99         fputc('"', out);
 100 }
 101
 102 #define fputs_quoted(_d, _o)            fputs_quoted_case(_d, _o, 0)
 103 #define fputs_quoted_upper(_d, _o)      fputs_quoted_case(_d, _o, 1)
 104 #define fputs_quoted_lower(_d, _o)      fputs_quoted_case(_d, _o, -1)
 105
 106 static inline void fputs_nonblank(const char *data, FILE *out)
 107 {
 108         const char *p;
 109
 110         for (p = data; p && *p; p++) {
 111                 if (isblank((unsigned char) *p) ||
 112                     (unsigned char) *p == 0x5c ||               /* \ */
 113                     !isprint((unsigned char) *p) ||
 114                     iscntrl((unsigned char) *p)) {
 115
 116                         fprintf(out, "\\x%02x", (unsigned char) *p);
 117
 118                 } else
 119                         fputc(*p, out);
 120         }
 121 }
 122
 123 #endif  /*  _CAREFULPUTC_H  */