1 #include "common.h"
2
3 /* expand a path relative to some `.' */
4 extern String *
abspath(char * path,char * dot,String * to)5 abspath(char *path, char *dot, String *to)
6 {
7 if (*path == '/') {
8 to = s_append(to, path);
9 } else {
10 to = s_append(to, dot);
11 to = s_append(to, "/");
12 to = s_append(to, path);
13 }
14 return to;
15 }
16
17 /* return a pointer to the base component of a pathname */
18 extern char *
basename(char * path)19 basename(char *path)
20 {
21 char *cp;
22
23 cp = strrchr(path, '/');
24 return cp==0 ? path : cp+1;
25 }
26
27 /* append a sub-expression match onto a String */
28 extern void
append_match(Resub * subexp,String * sp,int se)29 append_match(Resub *subexp, String *sp, int se)
30 {
31 char *cp, *ep;
32
33 cp = subexp[se].sp;
34 ep = subexp[se].ep;
35 for (; cp < ep; cp++)
36 s_putc(sp, *cp);
37 s_terminate(sp);
38 }
39
40 /*
41 * check for shell characters in a String
42 */
43 static char *illegalchars = "\r\n";
44
45 extern int
shellchars(char * cp)46 shellchars(char *cp)
47 {
48 char *sp;
49
50 for(sp=illegalchars; *sp; sp++)
51 if(strchr(cp, *sp))
52 return 1;
53 return 0;
54 }
55
56 static char *specialchars = " ()<>{};=\\'\`^&|";
57 static char *escape = "%%";
58
59 int
hexchar(int x)60 hexchar(int x)
61 {
62 x &= 0xf;
63 if(x < 10)
64 return '0' + x;
65 else
66 return 'A' + x - 10;
67 }
68
69 /*
70 * rewrite a string to escape shell characters
71 */
72 extern String*
escapespecial(String * s)73 escapespecial(String *s)
74 {
75 String *ns;
76 char *sp;
77
78 for(sp = specialchars; *sp; sp++)
79 if(strchr(s_to_c(s), *sp))
80 break;
81 if(*sp == 0)
82 return s;
83
84 ns = s_new();
85 for(sp = s_to_c(s); *sp; sp++){
86 if(strchr(specialchars, *sp)){
87 s_append(ns, escape);
88 s_putc(ns, hexchar(*sp>>4));
89 s_putc(ns, hexchar(*sp));
90 } else
91 s_putc(ns, *sp);
92 }
93 s_terminate(ns);
94 s_free(s);
95 return ns;
96 }
97
98 int
hex2uint(char x)99 hex2uint(char x)
100 {
101 if(x >= '0' && x <= '9')
102 return x - '0';
103 if(x >= 'A' && x <= 'F')
104 return (x - 'A') + 10;
105 if(x >= 'a' && x <= 'f')
106 return (x - 'a') + 10;
107 return -512;
108 }
109
110 /*
111 * rewrite a string to remove shell characters escapes
112 */
113 extern String*
unescapespecial(String * s)114 unescapespecial(String *s)
115 {
116 int c;
117 String *ns;
118 char *sp;
119 uint n;
120
121 if(strstr(s_to_c(s), escape) == 0)
122 return s;
123 n = strlen(escape);
124
125 ns = s_new();
126 for(sp = s_to_c(s); *sp; sp++){
127 if(strncmp(sp, escape, n) == 0){
128 c = (hex2uint(sp[n])<<4) | hex2uint(sp[n+1]);
129 if(c < 0)
130 s_putc(ns, *sp);
131 else {
132 s_putc(ns, c);
133 sp += n+2-1;
134 }
135 } else
136 s_putc(ns, *sp);
137 }
138 s_terminate(ns);
139 s_free(s);
140 return ns;
141
142 }
143
144 int
returnable(char * path)145 returnable(char *path)
146 {
147
148 return strcmp(path, "/dev/null") != 0;
149 }
150