1STAT(P) POSIX Programmer's Manual STAT(P)
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6 stat - get file status
7
9 #include <sys/stat.h>
10 int stat(const char *restrict path, struct stat *restrict buf);
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15 The stat() function shall obtain information about the named file and
16 write it to the area pointed to by the buf argument. The path argument
17 points to a pathname naming a file. Read, write, or execute permission
18 of the named file is not required. An implementation that provides
19 additional or alternate file access control mechanisms may, under
20 implementation-defined conditions, cause stat() to fail. In particular,
21 the system may deny the existence of the file specified by path.
22 If the named file is a symbolic link, the stat() function shall con‐
24 tinue pathname resolution using the contents of the symbolic link, and
25 shall return information pertaining to the resulting file if the file
26 exists.
27 The buf argument is a pointer to a stat structure, as defined in the
29 <sys/stat.h> header, into which information is placed concerning the
30 file.
31 The stat() function shall update any time-related fields (as described
33 in the Base Definitions volume of IEEE Std 1003.1-2001, Section 4.7,
34 File Times Update), before writing into the stat structure.
35 Unless otherwise specified, the structure members st_mode, st_ino,
37 st_dev, st_uid, st_gid, st_atime, st_ctime, and st_mtime shall have
38 meaningful values for all file types defined in this volume of
39 IEEE Std 1003.1-2001. The value of the member st_nlink shall be set to
40 the number of links to the file.
41
43 Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
44 returned and errno set to indicate the error.
45
47 The stat() function shall fail if:
48 EACCES Search permission is denied for a component of the path prefix.
50 EIO An error occurred while reading from the file system.
52 ELOOP A loop exists in symbolic links encountered during resolution of
54 the path argument.
55 ENAMETOOLONG
57 The length of the path argument exceeds {PATH_MAX} or a pathname
58 component is longer than {NAME_MAX}.
59 ENOENT A component of path does not name an existing file or path is an
61 empty string.
62 ENOTDIR
64 A component of the path prefix is not a directory.
65 EOVERFLOW
67 The file size in bytes or the number of blocks allocated to the
68 file or the file serial number cannot be represented correctly
69 in the structure pointed to by buf.
70 The stat() function may fail if:
73 ELOOP More than {SYMLOOP_MAX} symbolic links were encountered during
75 resolution of the path argument.
76 ENAMETOOLONG
78 As a result of encountering a symbolic link in resolution of the
79 path argument, the length of the substituted pathname string
80 exceeded {PATH_MAX}.
81 EOVERFLOW
83 A value to be stored would overflow one of the members of the
84 stat structure.
85 The following sections are informative.
88
90 Obtaining File Status Information
91 The following example shows how to obtain file status information for a
92 file named /home/cnd/mod1. The structure variable buffer is defined for
93 the stat structure.
94 #include <sys/types.h>
97 #include <sys/stat.h>
98 #include <fcntl.h>
99 struct stat buffer;
102 int status;
103 ...
104 status = stat("/home/cnd/mod1", &buffer);
105 Getting Directory Information
107 The following example fragment gets status information for each entry
108 in a directory. The call to the stat() function stores file information
109 in the stat structure pointed to by statbuf. The lines that follow the
110 stat() call format the fields in the stat structure for presentation to
111 the user of the program.
112 #include <sys/types.h>
115 #include <sys/stat.h>
116 #include <dirent.h>
117 #include <pwd.h>
118 #include <grp.h>
119 #include <time.h>
120 #include <locale.h>
121 #include <langinfo.h>
122 #include <stdio.h>
123 #include <stdint.h>
124 struct dirent *dp;
127 struct stat statbuf;
128 struct passwd *pwd;
129 struct group *grp;
130 struct tm *tm;
131 char datestring[256];
132 ...
133 /* Loop through directory entries. */
134 while ((dp = readdir(dir)) != NULL) {
135 /* Get entry's information. */
138 if (stat(dp->d_name, &statbuf) == -1)
139 continue;
140 /* Print out type, permissions, and number of links. */
143 printf("%10.10s", sperm (statbuf.st_mode));
144 printf("%4d", statbuf.st_nlink);
145 /* Print out owner's name if it is found using getpwuid(). */
148 if ((pwd = getpwuid(statbuf.st_uid)) != NULL)
149 printf(" %-8.8s", pwd->pw_name);
150 else
151 printf(" %-8d", statbuf.st_uid);
152 /* Print out group name if it is found using getgrgid(). */
155 if ((grp = getgrgid(statbuf.st_gid)) != NULL)
156 printf(" %-8.8s", grp->gr_name);
157 else
158 printf(" %-8d", statbuf.st_gid);
159 /* Print size of file. */
162 printf(" %9jd", (intmax_t)statbuf.st_size);
163 tm = localtime(&statbuf.st_mtime);
166 /* Get localized date string. */
169 strftime(datestring, sizeof(datestring), nl_langinfo(D_T_FMT), tm);
170 printf(" %s %s\n", datestring, dp->d_name);
173 }
174
176 None.
177
179 The intent of the paragraph describing "additional or alternate file
180 access control mechanisms" is to allow a secure implementation where a
181 process with a label that does not dominate the file's label cannot
182 perform a stat() function. This is not related to read permission; a
183 process with a label that dominates the file's label does not need read
184 permission. An implementation that supports write-up operations could
185 fail fstat() function calls even though it has a valid file descriptor
186 open for writing.
187
189 None.
190
192 fstat() , lstat() , readlink() , symlink() , the Base Definitions vol‐
193 ume of IEEE Std 1003.1-2001, <sys/stat.h>, <sys/types.h>
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196 Portions of this text are reprinted and reproduced in electronic form
197 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
198 -- Portable Operating System Interface (POSIX), The Open Group Base
199 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
200 Electrical and Electronics Engineers, Inc and The Open Group. In the
201 event of any discrepancy between this version and the original IEEE and
202 The Open Group Standard, the original IEEE and The Open Group Standard
203 is the referee document. The original Standard can be obtained online
204 at http://www.opengroup.org/unix/online.html .
205IEEE/The Open Group 2003 STAT(P)