1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2010 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Common Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.opensource.org/licenses/cpl1.0.txt *
11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
12 * *
13 * Information and Software Systems Research *
14 * AT&T Research *
15 * Florham Park NJ *
16 * *
17 * Glenn Fowler <gsf@research.att.com> *
18 * David Korn <dgk@research.att.com> *
19 * Phong Vo <kpv@research.att.com> *
20 * *
21 ***********************************************************************/
22 #include "sfhdr.h"
23
24 /* Open a file/string for IO.
25 ** If f is not nil, it is taken as an existing stream that should be
26 ** closed and its structure reused for the new stream.
27 **
28 ** Written by Kiem-Phong Vo.
29 */
30
31 #if _BLD_sfio && defined(__EXPORT__)
32 #define extern __EXPORT__
33 #endif
34 extern
35 #undef extern
36
37 #if __STD_C
_sfopen(Sfio_t * f,const char * file,const char * mode)38 Sfio_t* _sfopen(Sfio_t* f, const char* file, const char* mode)
39 #else
40 Sfio_t* _sfopen(f,file,mode)
41 Sfio_t* f; /* old stream structure */
42 char* file; /* file/string to be opened */
43 char* mode; /* mode of the stream */
44 #endif
45 {
46 int fd, oldfd, oflags, sflags;
47 SFMTXDECL(f);
48
49 /* get the control flags */
50 if((sflags = _sftype(mode,&oflags,NIL(int*))) == 0)
51 return NIL(Sfio_t*);
52
53 /* changing the control flags */
54 if(f && !file && !((f->flags|sflags)&SF_STRING) )
55 { SFMTXENTER(f, NIL(Sfio_t*));
56
57 if(f->mode&SF_INIT ) /* stream uninitialized, ok to set flags */
58 { f->flags |= (sflags & (SF_FLAGS & ~SF_RDWR));
59
60 if((sflags &= SF_RDWR) != 0) /* reset read/write modes */
61 { f->flags = (f->flags & ~SF_RDWR) | sflags;
62
63 if((f->flags&SF_RDWR) == SF_RDWR)
64 f->bits |= SF_BOTH;
65 else f->bits &= ~SF_BOTH;
66
67 if(f->flags&SF_READ)
68 f->mode = (f->mode&~SF_WRITE)|SF_READ;
69 else f->mode = (f->mode&~SF_READ)|SF_WRITE;
70 }
71 }
72 else /* make sure there is no buffered data */
73 { if(sfsync(f) < 0)
74 SFMTXRETURN(f,NIL(Sfio_t*));
75 }
76
77 if(f->file >= 0 && (oflags &= (O_TEXT|O_BINARY|O_APPEND)) != 0 )
78 { /* set file access control */
79 int ctl = sysfcntlf(f->file, F_GETFL, 0);
80 ctl = (ctl & ~(O_TEXT|O_BINARY|O_APPEND)) | oflags;
81 sysfcntlf(f->file, F_SETFL, ctl);
82 }
83
84 SFMTXRETURN(f,f);
85 }
86
87 if(sflags&SF_STRING)
88 { f = sfnew(f,(char*)file,
89 file ? (size_t)strlen((char*)file) : (size_t)SF_UNBOUND,
90 -1,sflags);
91 }
92 else
93 { if(!file)
94 return NIL(Sfio_t*);
95
96 #if _has_oflags /* open the file */
97 while((fd = sysopenf((char*)file,oflags,SF_CREATMODE)) < 0 && errno == EINTR)
98 errno = 0;
99 #else
100 while((fd = sysopenf(file,oflags&O_ACCMODE)) < 0 && errno == EINTR)
101 errno = 0;
102 if(fd >= 0)
103 { if((oflags&(O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL) )
104 { CLOSE(fd); /* error: file already exists */
105 return NIL(Sfio_t*);
106 }
107 if(oflags&O_TRUNC ) /* truncate file */
108 { reg int tf;
109 while((tf = syscreatf(file,SF_CREATMODE)) < 0 &&
110 errno == EINTR)
111 errno = 0;
112 CLOSE(tf);
113 }
114 }
115 else if(oflags&O_CREAT)
116 { while((fd = syscreatf(file,SF_CREATMODE)) < 0 && errno == EINTR)
117 errno = 0;
118 if((oflags&O_ACCMODE) != O_WRONLY)
119 { /* the file now exists, reopen it for read/write */
120 CLOSE(fd);
121 while((fd = sysopenf(file,oflags&O_ACCMODE)) < 0 &&
122 errno == EINTR)
123 errno = 0;
124 }
125 }
126 #endif
127 if(fd < 0)
128 return NIL(Sfio_t*);
129
130 /* we may have to reset the file descriptor to its old value */
131 oldfd = f ? f->file : -1;
132 if((f = sfnew(f,NIL(char*),(size_t)SF_UNBOUND,fd,sflags)) && oldfd >= 0)
133 (void)sfsetfd(f,oldfd);
134 }
135
136 return f;
137 }
138
139 #if __STD_C
_sftype(reg const char * mode,int * oflagsp,int * uflagp)140 int _sftype(reg const char* mode, int* oflagsp, int* uflagp)
141 #else
142 int _sftype(mode, oflagsp, uflagp)
143 reg char* mode;
144 int* oflagsp;
145 int* uflagp;
146 #endif
147 {
148 reg int sflags, oflags, uflag;
149
150 if(!mode)
151 return 0;
152
153 /* construct the open flags */
154 sflags = oflags = uflag = 0;
155 while(1) switch(*mode++)
156 {
157 case 'a' :
158 sflags |= SF_WRITE | SF_APPENDWR;
159 oflags |= O_WRONLY | O_APPEND | O_CREAT;
160 continue;
161 case 'b' :
162 oflags |= O_BINARY;
163 continue;
164 case 'm' :
165 sflags |= SF_MTSAFE;
166 uflag = 0;
167 continue;
168 case 'r' :
169 sflags |= SF_READ;
170 oflags |= O_RDONLY;
171 continue;
172 case 's' :
173 sflags |= SF_STRING;
174 continue;
175 case 't' :
176 oflags |= O_TEXT;
177 continue;
178 case 'u' :
179 sflags &= ~SF_MTSAFE;
180 uflag = 1;
181 continue;
182 case 'w' :
183 sflags |= SF_WRITE;
184 oflags |= O_WRONLY | O_CREAT;
185 if(!(sflags&SF_READ))
186 oflags |= O_TRUNC;
187 continue;
188 case 'x' :
189 oflags |= O_EXCL;
190 continue;
191 case 'F':
192 /* stdio compatibility -- fd >= FOPEN_MAX (or other magic number) ok */
193 continue;
194 case 'W' :
195 sflags |= SF_WCWIDTH;
196 uflag = 0;
197 continue;
198 case '+' :
199 if(sflags)
200 sflags |= SF_READ|SF_WRITE;
201 continue;
202 default :
203 if(!(oflags&O_CREAT) )
204 oflags &= ~O_EXCL;
205 #if _WIN32 && !_WINIX
206 if(!(oflags&(O_BINARY|O_TEXT)))
207 oflags |= O_BINARY;
208 #endif
209 if((sflags&SF_RDWR) == SF_RDWR)
210 oflags = (oflags&~O_ACCMODE)|O_RDWR;
211 if(oflagsp)
212 *oflagsp = oflags;
213 if(uflagp)
214 *uflagp = uflag;
215 if((sflags&(SF_STRING|SF_RDWR)) == SF_STRING)
216 sflags |= SF_READ;
217 return sflags;
218 }
219 }
220