xref: /petsc/src/sys/fileio/ftest.c (revision d71ae5a4db6382e7f06317b8d368875286fe9008)
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   PetscCheck(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   #if !defined(PETSC_MISSING_GETGROUPS)
59   int    err;
60   #endif
61 
62   PetscFunctionBegin;
63   /* Get the number of supplementary group IDs */
64   #if !defined(PETSC_MISSING_GETGROUPS)
65   numGroups = getgroups(0, gid);
66   PetscCheck(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);
79   PetscCheck(err >= 0, PETSC_COMM_SELF, PETSC_ERR_SYS, "Unable to obtain supplementary group IDs");
80   #endif
81 
82   /* Test for accessibility */
83   if (fuid == uid) {
84     rbit = S_IRUSR;
85     wbit = S_IWUSR;
86     ebit = S_IXUSR;
87   } else {
88     int g;
89 
90     for (g = 0; g <= numGroups; g++) {
91       if (fgid == gid[g]) {
92         rbit = S_IRGRP;
93         wbit = S_IWGRP;
94         ebit = S_IXGRP;
95         break;
96       }
97     }
98   }
99   PetscCall(PetscFree(gid));
100 
101   if (mode == 'r') {
102     if (fmode & rbit) *flg = PETSC_TRUE;
103   } else if (mode == 'w') {
104     if (fmode & wbit) *flg = PETSC_TRUE;
105   } else if (mode == 'x') {
106     if (fmode & ebit) *flg = PETSC_TRUE;
107   }
108   PetscFunctionReturn(0);
109 }
110 
111 #endif /* PETSC_HAVE_ACCESS */
112 
113 static PetscErrorCode PetscGetFileStat(const char fname[], uid_t *fileUid, gid_t *fileGid, int *fileMode, PetscBool *exists)
114 {
115   struct stat    statbuf;
116   PetscErrorCode ierr;
117 
118   PetscFunctionBegin;
119   *fileMode = 0;
120   *exists   = PETSC_FALSE;
121 #if defined(PETSC_HAVE_STAT_NO_CONST)
122   ierr = stat((char *)fname, &statbuf);
123 #else
124   ierr = stat(fname, &statbuf);
125 #endif
126   if (ierr) {
127 #if defined(EOVERFLOW)
128     PetscCheck(errno != EOVERFLOW, PETSC_COMM_SELF, PETSC_ERR_SYS, "EOVERFLOW in stat(), configure PETSc --with-large-file-io=1 to support files larger than 2GiB");
129 #endif
130     PetscCall(PetscInfo(NULL, "System call stat() failed on file %s\n", fname));
131     *exists = PETSC_FALSE;
132   } else {
133     PetscCall(PetscInfo(NULL, "System call stat() succeeded on file %s\n", fname));
134     *exists   = PETSC_TRUE;
135     *fileUid  = statbuf.st_uid;
136     *fileGid  = statbuf.st_gid;
137     *fileMode = statbuf.st_mode;
138   }
139   PetscFunctionReturn(0);
140 }
141 
142 /*@C
143    PetscTestFile - checks for the existence of a file
144 
145    Not Collective
146 
147    Input Parameters:
148 +  fname - the filename
149 -  mode - either 'r', 'w', 'x' or '\0'
150 
151    Output Parameter:
152 .  flg - the file exists and satisfies the mode
153 
154    Level: intermediate
155 
156    Note:
157    If mode is '\0', no permissions checks are performed
158 
159 .seealso: `PetscTestDirectory()`, `PetscLs()`
160 @*/
161 PetscErrorCode PetscTestFile(const char fname[], char mode, PetscBool *flg)
162 {
163   uid_t     fuid;
164   gid_t     fgid;
165   int       fmode;
166   PetscBool exists;
167 
168   PetscFunctionBegin;
169   *flg = PETSC_FALSE;
170   if (!fname) PetscFunctionReturn(0);
171 
172   PetscCall(PetscGetFileStat(fname, &fuid, &fgid, &fmode, &exists));
173   if (!exists) PetscFunctionReturn(0);
174   /* Except for systems that have this broken stat macros (rare), this is the correct way to check for a regular file */
175   if (!S_ISREG(fmode)) PetscFunctionReturn(0);
176   /* return if asked to check for existence only */
177   if (mode == '\0') {
178     *flg = exists;
179     PetscFunctionReturn(0);
180   }
181   PetscCall(PetscTestOwnership(fname, mode, fuid, fgid, fmode, flg));
182   PetscFunctionReturn(0);
183 }
184 
185 /*@C
186    PetscTestDirectory - checks for the existence of a directory
187 
188    Not Collective
189 
190    Input Parameters:
191 +  dirname - the directory name
192 -  mode - either 'r', 'w', or 'x'
193 
194    Output Parameter:
195 .  flg - the directory exists and satisfies the mode
196 
197    Level: intermediate
198 
199 .seealso: `PetscTestFile()`, `PetscLs()`
200 @*/
201 PetscErrorCode PetscTestDirectory(const char dirname[], char mode, PetscBool *flg)
202 {
203   uid_t     fuid;
204   gid_t     fgid;
205   int       fmode;
206   PetscBool exists;
207 
208   PetscFunctionBegin;
209   *flg = PETSC_FALSE;
210   if (!dirname) PetscFunctionReturn(0);
211 
212   PetscCall(PetscGetFileStat(dirname, &fuid, &fgid, &fmode, &exists));
213   if (!exists) PetscFunctionReturn(0);
214   /* Except for systems that have this broken stat macros (rare), this
215      is the correct way to check for a directory */
216   if (!S_ISDIR(fmode)) PetscFunctionReturn(0);
217 
218   PetscCall(PetscTestOwnership(dirname, mode, fuid, fgid, fmode, flg));
219   PetscFunctionReturn(0);
220 }
221 
222 /*@C
223    PetscLs - produce a listing of the files in a directory
224 
225    Collective
226 
227    Input Parameters:
228 +  comm - the MPI communicator
229 .  dirname - the directory name
230 -  tlen - the length of the buffer found[]
231 
232    Output Parameters:
233 +  found - listing of files
234 -  flg - the directory exists
235 
236    Level: intermediate
237 
238 .seealso: `PetscTestFile()`, `PetscLs()`
239 @*/
240 PetscErrorCode PetscLs(MPI_Comm comm, const char dirname[], char found[], size_t tlen, PetscBool *flg)
241 {
242   size_t len;
243   char  *f, program[PETSC_MAX_PATH_LEN];
244   FILE  *fp;
245 
246   PetscFunctionBegin;
247   PetscCall(PetscStrcpy(program, "ls "));
248   PetscCall(PetscStrcat(program, dirname));
249 #if defined(PETSC_HAVE_POPEN)
250   PetscCall(PetscPOpen(comm, NULL, program, "r", &fp));
251 #else
252   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP_SYS, "Cannot run external programs on this machine");
253 #endif
254   f = fgets(found, tlen, fp);
255   if (f) *flg = PETSC_TRUE;
256   else *flg = PETSC_FALSE;
257   while (f) {
258     PetscCall(PetscStrlen(found, &len));
259     f = fgets(found + len, tlen - len, fp);
260   }
261   if (*flg) PetscCall(PetscInfo(NULL, "ls on %s gives \n%s\n", dirname, found));
262 #if defined(PETSC_HAVE_POPEN)
263   PetscCall(PetscPClose(comm, fp));
264 #else
265   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP_SYS, "Cannot run external programs on this machine");
266 #endif
267   PetscFunctionReturn(0);
268 }
269