Merge branch 'ew/rebase'
[git/git.git] / quote.c
1 #include "cache.h"
2 #include "quote.h"
3
4 /* Help to copy the thing properly quoted for the shell safety.
5 * any single quote is replaced with '\'', any exclamation point
6 * is replaced with '\!', and the whole thing is enclosed in a
7 *
8 * E.g.
9 * original sq_quote result
10 * name ==> name ==> 'name'
11 * a b ==> a b ==> 'a b'
12 * a'b ==> a'\''b ==> 'a'\''b'
13 * a!b ==> a'\!'b ==> 'a'\!'b'
14 */
15 #undef EMIT
16 #define EMIT(x) ( (++len < n) && (*bp++ = (x)) )
17
18 static inline int need_bs_quote(char c)
19 {
20 return (c == '\'' || c == '!');
21 }
22
23 size_t sq_quote_buf(char *dst, size_t n, const char *src)
24 {
25 char c;
26 char *bp = dst;
27 size_t len = 0;
28
29 EMIT('\'');
30 while ((c = *src++)) {
31 if (need_bs_quote(c)) {
32 EMIT('\'');
33 EMIT('\\');
34 EMIT(c);
35 EMIT('\'');
36 } else {
37 EMIT(c);
38 }
39 }
40 EMIT('\'');
41
42 if ( n )
43 *bp = 0;
44
45 return len;
46 }
47
48 char *sq_quote(const char *src)
49 {
50 char *buf;
51 size_t cnt;
52
53 cnt = sq_quote_buf(NULL, 0, src) + 1;
54 buf = xmalloc(cnt);
55 sq_quote_buf(buf, cnt, src);
56
57 return buf;
58 }
59
60 char *sq_dequote(char *arg)
61 {
62 char *dst = arg;
63 char *src = arg;
64 char c;
65
66 if (*src != '\'')
67 return NULL;
68 for (;;) {
69 c = *++src;
70 if (!c)
71 return NULL;
72 if (c != '\'') {
73 *dst++ = c;
74 continue;
75 }
76 /* We stepped out of sq */
77 switch (*++src) {
78 case '\0':
79 *dst = 0;
80 return arg;
81 case '\\':
82 c = *++src;
83 if (need_bs_quote(c) && *++src == '\'') {
84 *dst++ = c;
85 continue;
86 }
87 /* Fallthrough */
88 default:
89 return NULL;
90 }
91 }
92 }
93
94 /*
95 * C-style name quoting.
96 *
97 * Does one of three things:
98 *
99 * (1) if outbuf and outfp are both NULL, inspect the input name and
100 * counts the number of bytes that are needed to hold c_style
101 * quoted version of name, counting the double quotes around
102 * it but not terminating NUL, and returns it. However, if name
103 * does not need c_style quoting, it returns 0.
104 *
105 * (2) if outbuf is not NULL, it must point at a buffer large enough
106 * to hold the c_style quoted version of name, enclosing double
107 * quotes, and terminating NUL. Fills outbuf with c_style quoted
108 * version of name enclosed in double-quote pair. Return value
109 * is undefined.
110 *
111 * (3) if outfp is not NULL, outputs c_style quoted version of name,
112 * but not enclosed in double-quote pair. Return value is undefined.
113 */
114
115 static int quote_c_style_counted(const char *name, int namelen,
116 char *outbuf, FILE *outfp, int no_dq)
117 {
118 #undef EMIT
119 #define EMIT(c) \
120 (outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
121
122 #define EMITQ() EMIT('\\')
123
124 const char *sp;
125 int ch, count = 0, needquote = 0;
126
127 if (!no_dq)
128 EMIT('"');
129 for (sp = name; sp < name + namelen; sp++) {
130 ch = *sp;
131 if (!ch)
132 break;
133 if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
134 (ch == 0177)) {
135 needquote = 1;
136 switch (ch) {
137 case '\a': EMITQ(); ch = 'a'; break;
138 case '\b': EMITQ(); ch = 'b'; break;
139 case '\f': EMITQ(); ch = 'f'; break;
140 case '\n': EMITQ(); ch = 'n'; break;
141 case '\r': EMITQ(); ch = 'r'; break;
142 case '\t': EMITQ(); ch = 't'; break;
143 case '\v': EMITQ(); ch = 'v'; break;
144
145 case '\\': /* fallthru */
146 case '"': EMITQ(); break;
147 default:
148 /* octal */
149 EMITQ();
150 EMIT(((ch >> 6) & 03) + '0');
151 EMIT(((ch >> 3) & 07) + '0');
152 ch = (ch & 07) + '0';
153 break;
154 }
155 }
156 EMIT(ch);
157 }
158 if (!no_dq)
159 EMIT('"');
160 if (outbuf)
161 *outbuf = 0;
162
163 return needquote ? count : 0;
164 }
165
166 int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
167 {
168 int cnt = strlen(name);
169 return quote_c_style_counted(name, cnt, outbuf, outfp, no_dq);
170 }
171
172 /*
173 * C-style name unquoting.
174 *
175 * Quoted should point at the opening double quote. Returns
176 * an allocated memory that holds unquoted name, which the caller
177 * should free when done. Updates endp pointer to point at
178 * one past the ending double quote if given.
179 */
180
181 char *unquote_c_style(const char *quoted, const char **endp)
182 {
183 const char *sp;
184 char *name = NULL, *outp = NULL;
185 int count = 0, ch, ac;
186
187 #undef EMIT
188 #define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
189
190 if (*quoted++ != '"')
191 return NULL;
192
193 while (1) {
194 /* first pass counts and allocates, second pass fills */
195 for (sp = quoted; (ch = *sp++) != '"'; ) {
196 if (ch == '\\') {
197 switch (ch = *sp++) {
198 case 'a': ch = '\a'; break;
199 case 'b': ch = '\b'; break;
200 case 'f': ch = '\f'; break;
201 case 'n': ch = '\n'; break;
202 case 'r': ch = '\r'; break;
203 case 't': ch = '\t'; break;
204 case 'v': ch = '\v'; break;
205
206 case '\\': case '"':
207 break; /* verbatim */
208
209 case '0':
210 case '1':
211 case '2':
212 case '3':
213 case '4':
214 case '5':
215 case '6':
216 case '7':
217 /* octal */
218 ac = ((ch - '0') << 6);
219 if ((ch = *sp++) < '0' || '7' < ch)
220 return NULL;
221 ac |= ((ch - '0') << 3);
222 if ((ch = *sp++) < '0' || '7' < ch)
223 return NULL;
224 ac |= (ch - '0');
225 ch = ac;
226 break;
227 default:
228 return NULL; /* malformed */
229 }
230 }
231 EMIT(ch);
232 }
233
234 if (name) {
235 *outp = 0;
236 if (endp)
237 *endp = sp;
238 return name;
239 }
240 outp = name = xmalloc(count + 1);
241 }
242 }
243
244 void write_name_quoted(const char *prefix, int prefix_len,
245 const char *name, int quote, FILE *out)
246 {
247 int needquote;
248
249 if (!quote) {
250 no_quote:
251 if (prefix_len)
252 fprintf(out, "%.*s", prefix_len, prefix);
253 fputs(name, out);
254 return;
255 }
256
257 needquote = 0;
258 if (prefix_len)
259 needquote = quote_c_style_counted(prefix, prefix_len,
260 NULL, NULL, 0);
261 if (!needquote)
262 needquote = quote_c_style(name, NULL, NULL, 0);
263 if (needquote) {
264 fputc('"', out);
265 if (prefix_len)
266 quote_c_style_counted(prefix, prefix_len,
267 NULL, out, 1);
268 quote_c_style(name, NULL, out, 1);
269 fputc('"', out);
270 }
271 else
272 goto no_quote;
273 }