File: carefulputc.h

package info (click to toggle)
util-linux 2.36.1-8%2Bdeb11u2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 50,684 kB
  • sloc: ansic: 135,480; sh: 16,120; yacc: 1,171; makefile: 407; xml: 389; python: 316; csh: 37; sed: 16; perl: 15
file content (207 lines) | stat: -rw-r--r-- 4,913 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
#ifndef UTIL_LINUX_CAREFULPUTC_H
#define UTIL_LINUX_CAREFULPUTC_H

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#ifdef HAVE_WIDECHAR
#include <wctype.h>
#include <wchar.h>
#endif
#include <stdbool.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;
}

/*
 * Requirements enumerated via testing (V8, Firefox, IE11):
 *
 * var charsToEscape = [];
 * for (var i = 0; i < 65535; i += 1) {
 *	try {
 *		JSON.parse('{"sample": "' + String.fromCodePoint(i) + '"}');
 *	} catch (e) {
 *		charsToEscape.push(i);
 *	}
 * }
 */
static inline void fputs_quoted_case_json(const char *data, FILE *out, int dir)
{
	const char *p;

	fputc('"', out);
	for (p = data; p && *p; p++) {

		const unsigned char c = (unsigned char) *p;

		/* From http://www.json.org
		 *
		 * The double-quote and backslashes would break out a string or
		 * init an escape sequence if not escaped.
		 *
		 * Note that single-quotes and forward slashes, while they're
		 * in the JSON spec, don't break double-quoted strings.
		 */
		if (c == '"' || c == '\\') {
			fputc('\\', out);
			fputc(c, out);
			continue;
		}

		/* All non-control characters OK; do the case swap as required. */
		if (c >= 0x20) {
			fputc(dir ==  1 ? toupper(c) :
			      dir == -1 ? tolower(c) : *p, out);
			continue;
		}

		/* In addition, all chars under ' ' break Node's/V8/Chrome's, and
		 * Firefox's JSON.parse function
		 */
		switch (c) {
			/* Handle short-hand cases to reduce output size.  C
			 * has most of the same stuff here, so if there's an
			 * "Escape for C" function somewhere in the STL, we
			 * should probably be using it.
			 */
			case '\b':
				fputs("\\b", out);
				break;
			case '\t':
				fputs("\\t", out);
				break;
			case '\n':
				fputs("\\n", out);
				break;
			case '\f':
				fputs("\\f", out);
				break;
			case '\r':
				fputs("\\r", out);
				break;
			default:
				/* Other assorted control characters */
				fprintf(out, "\\u00%02x", c);
				break;
		}
	}
	fputc('"', out);
}


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)

#define fputs_quoted_json(_d, _o)       fputs_quoted_case_json(_d, _o, 0)
#define fputs_quoted_json_upper(_d, _o) fputs_quoted_case_json(_d, _o, 1)
#define fputs_quoted_json_lower(_d, _o) fputs_quoted_case_json(_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  */