xref: /petsc/src/sys/fileio/ftest.c (revision ffa8c5705e8ab2cf85ee1d14dbe507a6e2eb5283)
1 
2 #include <petscsys.h>
3 #include <errno.h>
4 #if defined(PETSC_HAVE_PWD_H)
5 #include <pwd.h>
6 #endif
7 #include <ctype.h>
8 #include <sys/stat.h>
9 #if defined(PETSC_HAVE_UNISTD_H)
10 #include <unistd.h>
11 #endif
12 #if defined(PETSC_HAVE_SYS_UTSNAME_H)
13 #include <sys/utsname.h>
14 #endif
15 #if defined(PETSC_HAVE_IO_H)
16 #include <io.h>
17 #endif
18 #if defined(PETSC_HAVE_SYS_SYSTEMINFO_H)
19 #include <sys/systeminfo.h>
20 #endif
21 
22 #if defined(PETSC_HAVE__ACCESS) || defined(PETSC_HAVE_ACCESS)
23 
24 static PetscErrorCode PetscTestOwnership(const char fname[], char mode, uid_t fuid, gid_t fgid, int fmode, PetscBool  *flg)
25 {
26   int            m = R_OK;
27 
28   PetscFunctionBegin;
29   if (mode == 'r') m = R_OK;
30   else if (mode == 'w') m = W_OK;
31   else if (mode == 'x') m = X_OK;
32   else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG, "Mode must be one of r, w, or x");
33 #if defined(PETSC_HAVE_ACCESS)
34   if (!access(fname, m)) {
35     PetscCall(PetscInfo(NULL,"System call access() succeeded on file %s\n",fname));
36     *flg = PETSC_TRUE;
37   } else {
38     PetscCall(PetscInfo(NULL,"System call access() failed on file %s\n",fname));
39     *flg = PETSC_FALSE;
40   }
41 #else
42   PetscCheckFalse(m == X_OK,PETSC_COMM_SELF,PETSC_ERR_SUP, "Unable to check execute permission for file %s", fname);
43   if (!_access(fname, m)) *flg = PETSC_TRUE;
44 #endif
45   PetscFunctionReturn(0);
46 }
47 
48 #else  /* PETSC_HAVE_ACCESS or PETSC_HAVE__ACCESS */
49 
50 static PetscErrorCode PetscTestOwnership(const char fname[], char mode, uid_t fuid, gid_t fgid, int fmode, PetscBool  *flg)
51 {
52   uid_t          uid;
53   gid_t          *gid = NULL;
54   int            numGroups;
55   int            rbit = S_IROTH;
56   int            wbit = S_IWOTH;
57   int            ebit = S_IXOTH;
58   PetscErrorCode ierr;
59 #if !defined(PETSC_MISSING_GETGROUPS)
60   int            err;
61 #endif
62 
63   PetscFunctionBegin;
64   /* Get the number of supplementary group IDs */
65 #if !defined(PETSC_MISSING_GETGROUPS)
66   numGroups = getgroups(0, gid); PetscCheckFalse(numGroups < 0,PETSC_COMM_SELF,PETSC_ERR_SYS, "Unable to count supplementary group IDs");
67   PetscCall(PetscMalloc1(numGroups+1, &gid));
68 #else
69   numGroups = 0;
70 #endif
71 
72   /* Get the (effective) user and group of the caller */
73   uid    = geteuid();
74   gid[0] = getegid();
75 
76   /* Get supplementary group IDs */
77 #if !defined(PETSC_MISSING_GETGROUPS)
78   err = getgroups(numGroups, gid+1); PetscCheckFalse(err < 0,PETSC_COMM_SELF,PETSC_ERR_SYS, "Unable to obtain supplementary group IDs");
79 #endif
80 
81   /* Test for accessibility */
82   if (fuid == uid) {
83     rbit = S_IRUSR;
84     wbit = S_IWUSR;
85     ebit = S_IXUSR;
86   } else {
87     int g;
88 
89     for (g = 0; g <= numGroups; g++) {
90       if (fgid == gid[g]) {
91         rbit = S_IRGRP;
92         wbit = S_IWGRP;
93         ebit = S_IXGRP;
94         break;
95       }
96     }
97   }
98   PetscCall(PetscFree(gid));
99 
100   if (mode == 'r') {
101     if (fmode & rbit) *flg = PETSC_TRUE;
102   } else if (mode == 'w') {
103     if (fmode & wbit) *flg = PETSC_TRUE;
104   } else if (mode == 'x') {
105     if (fmode & ebit) *flg = PETSC_TRUE;
106   }
107   PetscFunctionReturn(0);
108 }
109 
110 #endif /* PETSC_HAVE_ACCESS */
111 
112 static PetscErrorCode PetscGetFileStat(const char fname[], uid_t *fileUid, gid_t *fileGid, int *fileMode,PetscBool  *exists)
113 {
114   struct stat    statbuf;
115   PetscErrorCode ierr;
116 
117   PetscFunctionBegin;
118   *fileMode = 0;
119   *exists = PETSC_FALSE;
120 #if defined(PETSC_HAVE_STAT_NO_CONST)
121   ierr = stat((char*) fname, &statbuf);
122 #else
123   ierr = stat(fname, &statbuf);
124 #endif
125   if (ierr) {
126 #if defined(EOVERFLOW)
127     PetscCheckFalse(errno == EOVERFLOW,PETSC_COMM_SELF,PETSC_ERR_SYS,"EOVERFLOW in stat(), configure PETSc --with-large-file-io=1 to support files larger than 2GiB");
128 #endif
129     PetscCall(PetscInfo(NULL,"System call stat() failed on file %s\n",fname));
130     *exists = PETSC_FALSE;
131   } else {
132     PetscCall(PetscInfo(NULL,"System call stat() succeeded on file %s\n",fname));
133     *exists   = PETSC_TRUE;
134     *fileUid  = statbuf.st_uid;
135     *fileGid  = statbuf.st_gid;
136     *fileMode = statbuf.st_mode;
137   }
138   PetscFunctionReturn(0);
139 }
140 
141 /*@C
142    PetscTestFile - checks for the existence of a file
143 
144    Not Collective
145 
146    Input Parameters:
147 +  fname - the filename
148 -  mode - either 'r', 'w', 'x' or '\0'
149 
150    Output Parameter:
151 .  flg - the file exists and satisfies the mode
152 
153    Level: intermediate
154 
155    Notes: if mode is '\0', no permissions checks are performed
156 
157 .seealso: PetscTestDirectory(), PetscLs()
158 @*/
159 PetscErrorCode  PetscTestFile(const char fname[], char mode, PetscBool  *flg)
160 {
161   uid_t          fuid;
162   gid_t          fgid;
163   int            fmode;
164   PetscBool      exists;
165 
166   PetscFunctionBegin;
167   *flg = PETSC_FALSE;
168   if (!fname) PetscFunctionReturn(0);
169 
170   PetscCall(PetscGetFileStat(fname, &fuid, &fgid, &fmode, &exists));
171   if (!exists) PetscFunctionReturn(0);
172   /* Except for systems that have this broken stat macros (rare), this is the correct way to check for a regular file */
173   if (!S_ISREG(fmode)) PetscFunctionReturn(0);
174   /* return if asked to check for existence only */
175   if (mode == '\0') { *flg = exists; PetscFunctionReturn(0); }
176   PetscCall(PetscTestOwnership(fname, mode, fuid, fgid, fmode, flg));
177   PetscFunctionReturn(0);
178 }
179 
180 /*@C
181    PetscTestDirectory - checks for the existence of a directory
182 
183    Not Collective
184 
185    Input Parameters:
186 +  dirname - the directory name
187 -  mode - either 'r', 'w', or 'x'
188 
189    Output Parameter:
190 .  flg - the directory exists and satisfies the mode
191 
192    Level: intermediate
193 
194 .seealso: PetscTestFile(), PetscLs()
195 @*/
196 PetscErrorCode  PetscTestDirectory(const char dirname[],char mode,PetscBool  *flg)
197 {
198   uid_t          fuid;
199   gid_t          fgid;
200   int            fmode;
201   PetscBool      exists;
202 
203   PetscFunctionBegin;
204   *flg = PETSC_FALSE;
205   if (!dirname) PetscFunctionReturn(0);
206 
207   PetscCall(PetscGetFileStat(dirname, &fuid, &fgid, &fmode,&exists));
208   if (!exists) PetscFunctionReturn(0);
209   /* Except for systems that have this broken stat macros (rare), this
210      is the correct way to check for a directory */
211   if (!S_ISDIR(fmode)) PetscFunctionReturn(0);
212 
213   PetscCall(PetscTestOwnership(dirname, mode, fuid, fgid, fmode, flg));
214   PetscFunctionReturn(0);
215 }
216 
217 /*@C
218    PetscLs - produce a listing of the files in a directory
219 
220    Collective
221 
222    Input Parameters:
223 +  comm - the MPI communicator
224 .  dirname - the directory name
225 -  tlen - the length of the buffer found[]
226 
227    Output Parameters:
228 +  found - listing of files
229 -  flg - the directory exists
230 
231    Level: intermediate
232 
233 .seealso: PetscTestFile(), PetscLs()
234 @*/
235 PetscErrorCode  PetscLs(MPI_Comm comm,const char dirname[],char found[],size_t tlen,PetscBool  *flg)
236 {
237   size_t         len;
238   char           *f,program[PETSC_MAX_PATH_LEN];
239   FILE           *fp;
240 
241   PetscFunctionBegin;
242   PetscCall(PetscStrcpy(program,"ls "));
243   PetscCall(PetscStrcat(program,dirname));
244 #if defined(PETSC_HAVE_POPEN)
245   PetscCall(PetscPOpen(comm,NULL,program,"r",&fp));
246 #else
247   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP_SYS,"Cannot run external programs on this machine");
248 #endif
249   f = fgets(found,tlen,fp);
250   if (f) *flg = PETSC_TRUE;
251   else *flg = PETSC_FALSE;
252   while (f) {
253     PetscCall(PetscStrlen(found,&len));
254     f    = fgets(found+len,tlen-len,fp);
255   }
256   if (*flg) PetscCall(PetscInfo(NULL,"ls on %s gives \n%s\n",dirname,found));
257 #if defined(PETSC_HAVE_POPEN)
258   PetscCall(PetscPClose(comm,fp));
259 #else
260   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP_SYS,"Cannot run external programs on this machine");
261 #endif
262   PetscFunctionReturn(0);
263 }
264