| 402 |
mateuszvis |
1 |
|
|
|
2 |
#include "doserr.h"
|
|
|
3 |
#include "helpers.h"
|
|
|
4 |
|
|
|
5 |
#include "redir.h"
|
|
|
6 |
|
|
|
7 |
static unsigned short oldstdout = 0xffff;
|
|
|
8 |
|
|
|
9 |
/* parse commandline and performs necessary redirections. cmdline is
|
|
|
10 |
* modified so all redirections are cut out.
|
|
|
11 |
* returns 0 on success, non-zero otherwise */
|
|
|
12 |
int redir_parsecmd(char far *cmdline, char *BUFFER) {
|
|
|
13 |
unsigned short i;
|
|
|
14 |
unsigned short rediroffset_stdin = 0;
|
|
|
15 |
unsigned short rediroffset_stdout = 0;
|
|
|
16 |
unsigned short pipesoffsets[16];
|
|
|
17 |
unsigned short pipescount = 0;
|
|
|
18 |
|
|
|
19 |
/* NOTE:
|
|
|
20 |
*
|
|
|
21 |
* 1. while it is possible to type a command with multiple
|
|
|
22 |
* redirections, MSDOS executes only the last redirection.
|
|
|
23 |
*
|
|
|
24 |
* 2. the order in which >, < and | are provided on the command line does
|
|
|
25 |
* not seem to matter for MSDOS. piped commands are executed first (in
|
|
|
26 |
* the order they appear) and the result of the last one is redirected to
|
|
|
27 |
* whenever the last > points at.
|
|
|
28 |
*/
|
|
|
29 |
|
|
|
30 |
/* preset oldstdout to 0xffff in case no redirection is required */
|
|
|
31 |
oldstdout = 0xffff;
|
|
|
32 |
|
|
|
33 |
for (i = 0;; i++) {
|
|
|
34 |
if (cmdline[i] == '>') {
|
|
|
35 |
cmdline[i] = 0;
|
|
|
36 |
rediroffset_stdout = i + 1;
|
|
|
37 |
} else if (cmdline[i] == '<') {
|
|
|
38 |
cmdline[i] = 0;
|
|
|
39 |
rediroffset_stdin = i + 1;
|
|
|
40 |
} else if (cmdline[i] == '|') {
|
|
|
41 |
cmdline[i] = 0;
|
|
|
42 |
pipesoffsets[pipescount++] = i + 1;
|
|
|
43 |
} else if (cmdline[i] == 0) {
|
|
|
44 |
break;
|
|
|
45 |
}
|
|
|
46 |
}
|
|
|
47 |
|
|
|
48 |
if (rediroffset_stdin != 0) {
|
|
|
49 |
outputnl("ERROR: stdin redirection is not supported yet");
|
|
|
50 |
return(-1);
|
|
|
51 |
}
|
|
|
52 |
|
|
|
53 |
if (pipescount != 0) {
|
|
|
54 |
outputnl("ERROR: pipe redirections are not supported yet");
|
|
|
55 |
return(-1);
|
|
|
56 |
}
|
|
|
57 |
|
|
|
58 |
if (rediroffset_stdout != 0) {
|
|
|
59 |
unsigned short openflag = 0x12; /* used during the int 21h,ah=6c call */
|
|
|
60 |
unsigned short errcode = 0;
|
|
|
61 |
unsigned short handle = 0;
|
|
|
62 |
char far *ptr;
|
|
|
63 |
/* append? */
|
|
|
64 |
if (cmdline[rediroffset_stdout] == '>') {
|
|
|
65 |
openflag = 0x11;
|
|
|
66 |
rediroffset_stdout++;
|
|
|
67 |
}
|
|
|
68 |
|
|
|
69 |
/* copy dst file to BUFFER */
|
|
|
70 |
ptr = cmdline + rediroffset_stdout;
|
|
|
71 |
while (*ptr == ' ') ptr++; /* skip leading white spaces */
|
|
|
72 |
for (i = 0;; i++) {
|
|
|
73 |
BUFFER[i] = ptr[i];
|
|
|
74 |
if ((BUFFER[i] == ' ') || (BUFFER[i] == 0)) break;
|
|
|
75 |
}
|
|
|
76 |
BUFFER[i] = 0;
|
|
|
77 |
|
|
|
78 |
/* */
|
|
|
79 |
_asm {
|
|
|
80 |
push ax
|
|
|
81 |
push bx
|
|
|
82 |
push cx
|
|
|
83 |
push dx
|
|
|
84 |
push si
|
|
|
85 |
mov ax, 0x6c00 /* Extended Open/Create */
|
|
|
86 |
mov bx, 1 /* access mode (0=read, 1=write, 2=r+w */
|
|
|
87 |
xor cx, cx /* attributes when(if) creating the file (0=normal) */
|
|
|
88 |
mov dx, [openflag] /* action if file exists (0x11=open, 0x12=truncate)*/
|
|
|
89 |
mov si, BUFFER /* ASCIIZ filename */
|
|
|
90 |
int 0x21 /* AX=handle on success (CF clear), otherwise dos err */
|
|
|
91 |
mov [handle], ax /* save the file handler */
|
|
|
92 |
jnc DUPSTDOUT
|
|
|
93 |
mov [errcode], ax
|
|
|
94 |
jmp DONE
|
|
|
95 |
DUPSTDOUT:
|
|
|
96 |
/* save (duplicate) current stdout so I can revert it later */
|
|
|
97 |
mov ah, 0x45 /* duplicate file handle */
|
|
|
98 |
mov bx, 1 /* handle to dup (1=stdout) */
|
|
|
99 |
int 0x21 /* ax = new file handle */
|
|
|
100 |
mov [oldstdout], ax
|
|
|
101 |
/* redirect the stdout handle */
|
|
|
102 |
mov bx, [handle] /* dst handle */
|
|
|
103 |
mov cx, 1 /* src handle (1=stdout) */
|
|
|
104 |
mov ah, 0x46 /* redirect a handle */
|
|
|
105 |
int 0x21
|
|
|
106 |
/* close the original file handle (no longer needed) */
|
|
|
107 |
mov ah, 0x3e /* close a file handle (handle in BX) */
|
|
|
108 |
int 0x21
|
|
|
109 |
DONE:
|
|
|
110 |
pop si
|
|
|
111 |
pop dx
|
|
|
112 |
pop cx
|
|
|
113 |
pop bx
|
|
|
114 |
pop ax
|
|
|
115 |
}
|
|
|
116 |
if (errcode != 0) {
|
|
|
117 |
outputnl(doserr(errcode));
|
|
|
118 |
return(-1);
|
|
|
119 |
}
|
|
|
120 |
}
|
|
|
121 |
|
|
|
122 |
return(0);
|
|
|
123 |
}
|
|
|
124 |
|
|
|
125 |
|
|
|
126 |
/* restores previous stdout/stdin handlers if they have been redirected */
|
|
|
127 |
void redir_revert(void) {
|
|
|
128 |
_asm {
|
|
|
129 |
/* if oldstdout is 0xffff then not redirected */
|
|
|
130 |
cmp word ptr [oldstdout], 0xffff
|
|
|
131 |
je DONE
|
|
|
132 |
/* redirect the stdout handle */
|
|
|
133 |
mov bx, [oldstdout] /* dst handle */
|
|
|
134 |
mov cx, 1 /* src handle (1=stdout) */
|
|
|
135 |
mov ah, 0x46 /* redirect a handle */
|
|
|
136 |
int 0x21
|
|
|
137 |
mov [oldstdout], 0xffff
|
|
|
138 |
DONE:
|
|
|
139 |
}
|
|
|
140 |
}
|