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 #ifdef HAVE_WIDECHAR
   8 #include <wctype.h>
   9 #include <wchar.h>
  10 #endif
  11 #include <stdbool.h>
  12
  13 #include "cctype.h"
  14
  15 /*
  16  * A puts() for use in write and wall (that sometimes are sgid tty).
  17  * It avoids control and invalid characters.
  18  * The locale of the recipient is nominally unknown,
  19  * but it's a solid bet that it's compatible with the author's.
  20  * Use soft_width=0 to disable wrapping.
  21  */
  22 static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf, int soft_width)
  23 {
  24         int ret = 0, col = 0;
  25
  26         for (size_t slen = strlen(s); *s; ++s, --slen) {
  27                 if (*s == '\t')
  28                         col += (7 - (col % 8)) - 1;
  29                 else if (*s == '\r')
  30                         col = -1;
  31                 else if (*s == '\a')
  32                         --col;
  33
  34                 if ((soft_width && col >= soft_width) || *s == '\n') {
  35                         if (soft_width) {
  36                                 fprintf(fp, "%*s", soft_width - col, "");
  37                                 col = 0;
  38                         }
  39                         ret = fputs(cr_lf ? "\r\n" : "\n", fp);
  40                         if (*s == '\n' || ret < 0)
  41                                 goto wrote;
  42                 }
  43
  44                 if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r') {
  45                         ret = putc(*s, fp);
  46                         ++col;
  47                 } else if (!c_isascii(*s)) {
  48 #ifdef HAVE_WIDECHAR
  49                         wchar_t w;
  50                         size_t clen = mbtowc(&w, s, slen);
  51                         switch(clen) {
  52                                 case (size_t)-2:  // incomplete
  53                                 case (size_t)-1:  // EILSEQ
  54                                         mbtowc(NULL, NULL, 0);
  55                                 nonprint:
  56                                         col += ret = fprintf(fp, "\\%3hho", *s);
  57                                         break;
  58                                 default:
  59                                         if(!iswprint(w))
  60                                                 goto nonprint;
  61                                         ret = fwrite(s, 1, clen, fp);
  62                                         if (soft_width)
  63                                                 col += wcwidth(w);
  64                                         s += clen - 1;
  65                                         slen -= clen - 1;
  66                                         break;
  67                         }
  68 #else
  69                         col += ret = fprintf(fp, "\\%3hho", *s);
  70 #endif
  71                 } else {
  72                         ret = fputs((char[]){ ctrl, *s ^ 0x40, '\0' }, fp);
  73                         col += 2;
  74                 }
  75
  76         wrote:
  77                 if (ret < 0)
  78                         return EOF;
  79         }
  80         return 0;
  81 }
  82
  83 static inline void fputs_quoted_case(const char *data, FILE *out, int dir)
  84 {
  85         const char *p;
  86
  87         fputc('"', out);
  88         for (p = data; p && *p; p++) {
  89                 if ((unsigned char) *p == 0x22 ||               /* " */
  90                     (unsigned char) *p == 0x5c ||               /* \ */
  91                     (unsigned char) *p == 0x60 ||               /* ` */
  92                     (unsigned char) *p == 0x24 ||               /* $ */
  93                     !isprint((unsigned char) *p) ||
  94                     iscntrl((unsigned char) *p)) {
  95
  96                         fprintf(out, "\\x%02x", (unsigned char) *p);
  97                 } else
  98                         fputc(dir ==  1 ? toupper(*p) :
  99                               dir == -1 ? tolower(*p) :
 100                               *p, out);
 101         }
 102         fputc('"', out);
 103 }
 104
 105 #define fputs_quoted(_d, _o)            fputs_quoted_case(_d, _o, 0)
 106 #define fputs_quoted_upper(_d, _o)      fputs_quoted_case(_d, _o, 1)
 107 #define fputs_quoted_lower(_d, _o)      fputs_quoted_case(_d, _o, -1)
 108
 109 static inline void fputs_nonblank(const char *data, FILE *out)
 110 {
 111         const char *p;
 112
 113         for (p = data; p && *p; p++) {
 114                 if (isblank((unsigned char) *p) ||
 115                     (unsigned char) *p == 0x5c ||               /* \ */
 116                     !isprint((unsigned char) *p) ||
 117                     iscntrl((unsigned char) *p)) {
 118
 119                         fprintf(out, "\\x%02x", (unsigned char) *p);
 120
 121                 } else
 122                         fputc(*p, out);
 123         }
 124 }
 125
 126 #endif  /*  _CAREFULPUTC_H  */