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comparison examples/dsl/redirect.cpp @ 0:13d2b8934445

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Import AnaGram (near-)release tree into Mercurial.
author David A. Holland
date Sat, 22 Dec 2007 17:52:45 -0500
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children 607e3be6bad8
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-1:000000000000 0:13d2b8934445
1 /*****
2
3 AnaGram Programming Examples
4
5 A Dos Script Language
6 Redirection Class Module
7
8 Copyright 1993 Parsifal Software. All Rights Reserved.
9
10 This software is provided 'as-is', without any express or implied
11 warranty. In no event will the authors be held liable for any damages
12 arising from the use of this software.
13
14 Permission is granted to anyone to use this software for any purpose,
15 including commercial applications, and to alter it and redistribute it
16 freely, subject to the following restrictions:
17
18 1. The origin of this software must not be misrepresented; you must not
19 claim that you wrote the original software. If you use this software
20 in a product, an acknowledgment in the product documentation would be
21 appreciated but is not required.
22 2. Altered source versions must be plainly marked as such, and must not be
23 misrepresented as being the original software.
24 3. This notice may not be removed or altered from any source distribution.
25
26 *****/
27
28 #include "redirect.h"
29 #include "assert.h"
30 #include "util.h"
31
32 // Constructors
33
34 redirect::redirect(int h) {
35 int temp;
36 handle = h;
37 #if defined(__MSDOS__) || defined(__WINDOWS__)
38 tmpnam(name);
39 temp = open(name, O_CREAT | O_RDWR | O_TEXT, S_IREAD | S_IWRITE);
40 #else
41 /* tmpnam() is unsafe, and causes a warning from many Unix linkers */
42 strcpy(name, ".dsl.XXXXXX");
43 temp = mkstemp(name);
44 #endif
45 assert(temp >= 0);
46 old_handle = dup(handle);
47 dup2(temp, handle);
48 close(temp);
49 copy_flag = 0; // live
50 }
51
52 redirect::redirect(int h, char *file_name, int append_flag) {
53 int temp;
54 int flag;
55 handle = h;
56 temp = open(file_name, O_CREAT | O_RDWR | O_TEXT, S_IREAD | S_IWRITE);
57 if (append_flag) lseek(temp, 0L, SEEK_END);
58 name[0] = 0;
59 assert(temp >= 0);
60 old_handle = dup(handle);
61 flag = dup2(temp, handle);
62 assert(flag == 0);
63 close(temp);
64 copy_flag = 0; // live
65 }
66
67 redirect::redirect(redirect &r) {
68 *this = r;
69 copy_flag++; // memorex
70 }
71
72
73 // Destructor
74
75 redirect::~redirect() {
76 if (copy_flag) return;
77 dup2(old_handle, handle);
78 close(old_handle);
79 if (name[0]) unlink(name);
80 }
81
82
83 // Save temporary file
84
85 char *save_file(redirect &s) {
86 assert(s.copy_flag == 0);
87 char *result = memdup(s.name, 1+strlen(s.name));
88 s.name[0] = 0;
89 return result;
90 }
91
92
93 // Extract content of file
94
95 char *content(redirect &s) {
96 long length = filelength(s.handle);
97 long where = tell(s.handle); // Current file position
98 unsigned n;
99 char *result;
100
101 assert(length < 65520L);
102 n = (unsigned) (length + 1);
103 result = new char[n];
104 assert(result != NULL);
105 lseek(s.handle,0,0);
106 n = read(s.handle, result, (unsigned) length);
107 lseek(s.handle,where,0); // Restore file
108 result[n] = 0; // Terminate string
109 return result;
110 }
111
112