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
|
#include "mk.h"
static int bquote(Biobuf*, Bufblock*);
/*
* Assemble a line skipping blank lines, comments, and eliding
* escaped newlines
*/
int
assline(Biobuf *bp, Bufblock *buf)
{
int c;
int lastc;
buf->current=buf->start;
while ((c = nextrune(bp, 1)) >= 0){
switch(c)
{
case '\r': /* consumes CRs for Win95 */
continue;
case '\n':
if (buf->current != buf->start) {
insert(buf, 0);
return 1;
}
break; /* skip empty lines */
case '\\':
case '\'':
case '"':
rinsert(buf, c);
if (shellt->escapetoken(bp, buf, 1, c) == 0)
Exit();
break;
case '`':
if (bquote(bp, buf) == 0)
Exit();
break;
case '#':
lastc = '#';
while ((c = Bgetc(bp)) != '\n') {
if (c < 0)
goto eof;
if(c != '\r')
lastc = c;
}
mkinline++;
if (lastc == '\\')
break; /* propagate escaped newlines??*/
if (buf->current != buf->start) {
insert(buf, 0);
return 1;
}
break;
default:
rinsert(buf, c);
break;
}
}
eof:
insert(buf, 0);
return *buf->start != 0;
}
/*
* assemble a back-quoted shell command into a buffer
*/
static int
bquote(Biobuf *bp, Bufblock *buf)
{
int c, line, term;
int start;
line = mkinline;
while((c = Bgetrune(bp)) == ' ' || c == '\t')
;
if(c == '{'){
term = '}'; /* rc style */
while((c = Bgetrune(bp)) == ' ' || c == '\t')
;
} else
term = '`'; /* sh style */
start = buf->current-buf->start;
for(;c > 0; c = nextrune(bp, 0)){
if(c == term){
insert(buf, '\n');
insert(buf,0);
buf->current = buf->start+start;
execinit();
execsh(0, buf->current, buf, envy, shellt, shellcmd);
return 1;
}
if(c == '\n')
break;
if(c == '\'' || c == '"' || c == '\\'){
insert(buf, c);
if(!shellt->escapetoken(bp, buf, 1, c))
return 0;
continue;
}
rinsert(buf, c);
}
SYNERR(line);
fprint(2, "missing closing %c after `\n", term);
return 0;
}
/*
* get next character stripping escaped newlines
* the flag specifies whether escaped newlines are to be elided or
* replaced with a blank.
*/
int
nextrune(Biobuf *bp, int elide)
{
int c, c2;
static int savec;
if(savec){
c = savec;
savec = 0;
return c;
}
for (;;) {
c = Bgetrune(bp);
if (c == '\\') {
c2 = Bgetrune(bp);
if(c2 == '\r'){
savec = c2;
c2 = Bgetrune(bp);
}
if (c2 == '\n') {
savec = 0;
mkinline++;
if (elide)
continue;
return ' ';
}
Bungetrune(bp);
}
if (c == '\n')
mkinline++;
return c;
}
}
|
