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