1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2012 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Eclipse Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.eclipse.org/org/documents/epl-v10.html *
11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
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, fflags, sflags;
47 SFMTXDECL(f);
48
49 /* get the control flags */
50 if((sflags = _sftype(mode,&oflags,&fflags,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 )
78 { if ((oflags &= (O_TEXT|O_BINARY|O_APPEND)) != 0 )
79 { /* set file access control */
80 int ctl = sysfcntlf(f->file, F_GETFL, 0);
81 ctl = (ctl & ~(O_TEXT|O_BINARY|O_APPEND)) | oflags;
82 sysfcntlf(f->file, F_SETFL, ctl);
83 }
84 #if !O_cloexec
85 if (fflags & SF_FD_CLOEXEC)
86 SETCLOEXEC(f->file);
87 #endif
88 }
89
90 SFMTXRETURN(f,f);
91 }
92
93 if(sflags&SF_STRING)
94 { f = sfnew(f,(char*)file,
95 file ? (size_t)strlen((char*)file) : (size_t)SF_UNBOUND,
96 -1,sflags);
97 }
98 else
99 { if(!file)
100 return NIL(Sfio_t*);
101
102 #if _has_oflags /* open the file */
103 while((fd = sysopenf((char*)file,oflags,SF_CREATMODE)) < 0 && errno == EINTR)
104 errno = 0;
105 #else
106 while((fd = sysopenf(file,oflags&O_ACCMODE)) < 0 && errno == EINTR)
107 errno = 0;
108 if(fd >= 0)
109 { if((oflags&(O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL) )
110 { CLOSE(fd); /* error: file already exists */
111 return NIL(Sfio_t*);
112 }
113 if(oflags&O_TRUNC ) /* truncate file */
114 { reg int tf;
115 while((tf = syscreatf(file,SF_CREATMODE)) < 0 &&
116 errno == EINTR)
117 errno = 0;
118 CLOSE(tf);
119 }
120 }
121 else if(oflags&O_CREAT)
122 { while((fd = syscreatf(file,SF_CREATMODE)) < 0 && errno == EINTR)
123 errno = 0;
124 if((oflags&O_ACCMODE) != O_WRONLY)
125 { /* the file now exists, reopen it for read/write */
126 CLOSE(fd);
127 while((fd = sysopenf(file,oflags&O_ACCMODE)) < 0 &&
128 errno == EINTR)
129 errno = 0;
130 }
131 }
132 #endif
133 if(fd < 0)
134 return NIL(Sfio_t*);
135
136 /* we may have to reset the file descriptor to its old value */
137 oldfd = f ? f->file : -1;
138 if((f = sfnew(f,NIL(char*),(size_t)SF_UNBOUND,fd,sflags)) && oldfd >= 0)
139 (void)sfsetfd(f,oldfd);
140 }
141
142 return f;
143 }
144
145 #if __STD_C
_sftype(reg const char * mode,int * oflagsp,int * fflagsp,int * uflagp)146 int _sftype(reg const char* mode, int* oflagsp, int* fflagsp, int* uflagp)
147 #else
148 int _sftype(mode, oflagsp, fflagsp, uflagp)
149 reg char* mode;
150 int* oflagsp;
151 int* fflagsp;
152 int* uflagp;
153 #endif
154 {
155 reg int sflags, oflags, fflags, uflag;
156
157 if(!mode)
158 return 0;
159
160 /* construct the open flags */
161 sflags = oflags = fflags = uflag = 0;
162 while(1) switch(*mode++)
163 {
164 case 'a' :
165 sflags |= SF_WRITE | SF_APPENDWR;
166 oflags |= O_WRONLY | O_APPEND | O_CREAT;
167 continue;
168 case 'b' :
169 oflags |= O_BINARY;
170 continue;
171 case 'e' :
172 oflags |= O_cloexec;
173 fflags |= SF_FD_CLOEXEC;
174 continue;
175 case 'm' :
176 sflags |= SF_MTSAFE;
177 uflag = 0;
178 continue;
179 case 'r' :
180 sflags |= SF_READ;
181 oflags |= O_RDONLY;
182 continue;
183 case 's' :
184 sflags |= SF_STRING;
185 continue;
186 case 't' :
187 oflags |= O_TEXT;
188 continue;
189 case 'u' :
190 sflags &= ~SF_MTSAFE;
191 uflag = 1;
192 continue;
193 case 'w' :
194 sflags |= SF_WRITE;
195 oflags |= O_WRONLY | O_CREAT;
196 if(!(sflags&SF_READ))
197 oflags |= O_TRUNC;
198 continue;
199 case 'x' :
200 oflags |= O_EXCL;
201 continue;
202 case 'F':
203 /* stdio compatibility -- fd >= FOPEN_MAX (or other magic number) ok */
204 continue;
205 case 'W' :
206 sflags |= SF_WCWIDTH;
207 uflag = 0;
208 continue;
209 case '+' :
210 if(sflags)
211 sflags |= SF_READ|SF_WRITE;
212 continue;
213 default :
214 if(!(oflags&O_CREAT) )
215 oflags &= ~O_EXCL;
216 #if _WIN32 && !_WINIX
217 if(!(oflags&(O_BINARY|O_TEXT)))
218 oflags |= O_BINARY;
219 #endif
220 if((sflags&SF_RDWR) == SF_RDWR)
221 oflags = (oflags&~O_ACCMODE)|O_RDWR;
222 if(oflagsp)
223 *oflagsp = oflags;
224 if(fflagsp)
225 *fflagsp = fflags;
226 if(uflagp)
227 *uflagp = uflag;
228 if((sflags&(SF_STRING|SF_RDWR)) == SF_STRING)
229 sflags |= SF_READ;
230 return sflags;
231 }
232 }
233