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1 | /* $Header: popen.c,v 3.0.1.1 90/03/27 16:11:57 lwall Locked $ |
2 | * |
3 | * (C) Copyright 1988, 1990 Diomidis Spinellis. |
4 | * |
5 | * You may distribute under the terms of the GNU General Public License |
6 | * as specified in the README file that comes with the perl 3.0 kit. |
7 | * |
8 | * $Log: popen.c,v $ |
9 | * Revision 3.0.1.1 90/03/27 16:11:57 lwall |
10 | * patch16: MSDOS support |
11 | * |
12 | * Revision 1.1 90/03/18 20:32:20 dds |
13 | * Initial revision |
14 | * |
15 | */ |
16 | |
17 | /* |
18 | * Popen and pclose for MS-DOS |
19 | */ |
20 | |
21 | #include <stdlib.h> |
22 | #include <stdio.h> |
23 | #include <process.h> |
24 | |
25 | /* |
26 | * Possible actions on an popened file |
27 | */ |
28 | enum action { |
29 | delete, /* Used for "r". Delete the tmp file */ |
30 | execute /* Used for "w". Execute the command. */ |
31 | }; |
32 | |
33 | /* |
34 | * Linked list of things to do at the end of the program execution. |
35 | */ |
36 | static struct todo { |
37 | FILE *f; /* File we are working on (to fclose) */ |
38 | const char *name; /* Name of the file (to unlink) */ |
39 | const char *command; /* Command to execute */ |
40 | enum action what; /* What to do (execute or delete) */ |
41 | struct todo *next; /* Next structure */ |
42 | } *todolist; |
43 | |
44 | |
45 | /* Clean up function */ |
46 | static int close_pipes(void); |
47 | |
48 | /* |
49 | * Add a file f running the command command on file name to the list |
50 | * of actions to be done at the end. The action is specified in what. |
51 | * Return -1 on failure, 0 if ok. |
52 | */ |
53 | static int |
54 | add(FILE *f, const char *command, const char *name, enum action what) |
55 | { |
56 | struct todo *p; |
57 | |
58 | if ((p = (struct todo *) malloc(sizeof(struct todo))) == NULL) |
59 | return -1; |
60 | p->f = f; |
61 | p->command = command; |
62 | p->name = name; |
63 | p->what = what; |
64 | p->next = todolist; |
65 | todolist = p; |
66 | return 0; |
67 | } |
68 | |
69 | FILE * |
70 | mypopen(const char *command, const char *t) |
71 | { |
72 | char buff[256]; |
73 | char *name; |
74 | FILE *f; |
75 | static init = 0; |
76 | |
77 | if (!init) |
78 | if (onexit(close_pipes) == NULL) |
79 | return NULL; |
80 | else |
81 | init++; |
82 | |
83 | if ((name = tempnam(getenv("TMP"), "pp")) == NULL) |
84 | return NULL; |
85 | |
86 | switch (*t) { |
87 | case 'r': |
88 | sprintf(buff, "%s >%s", command, name); |
89 | if (system(buff) || (f = fopen(name, "r")) == NULL) { |
90 | free(name); |
91 | return NULL; |
92 | } |
93 | if (add(f, command, name, delete)) { |
94 | (void)fclose(f); |
95 | (void)unlink(name); |
96 | free(name); |
97 | return NULL; |
98 | } |
99 | return f; |
100 | case 'w': |
101 | if ((f = fopen(name, "w")) == NULL) { |
102 | free(name); |
103 | return NULL; |
104 | } |
105 | if (add(f, command, name, execute)) { |
106 | (void)fclose(f); |
107 | (void)unlink(name); |
108 | free(name); |
109 | return NULL; |
110 | } |
111 | return f; |
112 | default: |
113 | free(name); |
114 | return NULL; |
115 | } |
116 | } |
117 | |
118 | int |
119 | mypclose(FILE *f) |
120 | { |
121 | struct todo *p, **prev; |
122 | char buff[256]; |
123 | const char *name; |
124 | int status; |
125 | |
126 | for (p = todolist, prev = &todolist; p; prev = &(p->next), p = p->next) |
127 | if (p->f == f) { |
128 | *prev = p->next; |
129 | name = p->name; |
130 | switch (p->what) { |
131 | case delete: |
132 | free(p); |
133 | if (fclose(f) == EOF) { |
134 | (void)unlink(name); |
135 | status = EOF; |
136 | } else if (unlink(name) < 0) |
137 | status = EOF; |
138 | else |
139 | status = 0; |
140 | free(name); |
141 | return status; |
142 | case execute: |
143 | (void)sprintf(buff, "%s <%s", p->command, p->name); |
144 | free(p); |
145 | if (system(buff)) { |
146 | (void)unlink(name); |
147 | status = EOF; |
148 | } else if (fclose(f) == EOF) { |
149 | (void)unlink(name); |
150 | status = EOF; |
151 | } else if (unlink(name) < 0) |
152 | status = EOF; |
153 | else |
154 | status = 0; |
155 | free(name); |
156 | return status; |
157 | default: |
158 | return EOF; |
159 | } |
160 | } |
161 | return EOF; |
162 | } |
163 | |
164 | /* |
165 | * Clean up at the end. Called by the onexit handler. |
166 | */ |
167 | static int |
168 | close_pipes(void) |
169 | { |
170 | struct todo *p; |
171 | |
172 | for (p = todolist; p; p = p->next) |
173 | (void)mypclose(p->f); |
174 | return 0; |
175 | } |