Add special rule to make cmdline.o.
[dss.git] / fd.c
1 #include <unistd.h>
2 #include <assert.h>
3 #include <string.h>
4 #include <errno.h>
5 #include <sys/types.h>
6 #include <dirent.h>
7 #include <sys/stat.h>
8 #include <fcntl.h>
9
10
11 #include "gcc-compat.h"
12 #include "error.h"
13 #include "string.h"
14
15 /**
16 * Call a function for each subdirectory of the current working directory.
17 *
18 * \param dirname The directory to traverse.
19 * \param func The function to call for each subdirecrtory.
20 * \param private_data Pointer to an arbitrary data structure.
21 *
22 * For each top-level directory under \a dirname, the supplied function \a func is
23 * called. The full path of the subdirectory and the \a private_data pointer
24 * are passed to \a func.
25 *
26 * \return This function returns immediately if \a func returned a negative
27 * value. In this case \a func must set error_txt and this negative value is
28 * returned to the caller. Otherwise the function returns when all
29 * subdirectories have been passed to \a func.
30 */
31
32 int for_each_subdir(int (*func)(const char *, void *), void *private_data)
33 {
34 struct dirent *entry;
35 int ret;
36 DIR *dir = opendir(".");
37
38 if (!dir)
39 return -ERRNO_TO_DSS_ERROR(errno);
40 while ((entry = readdir(dir))) {
41 mode_t m;
42 struct stat s;
43
44 if (!strcmp(entry->d_name, "."))
45 continue;
46 if (!strcmp(entry->d_name, ".."))
47 continue;
48 ret = lstat(entry->d_name, &s) == -1;
49 if (ret == -1) {
50 ret = -ERRNO_TO_DSS_ERROR(errno);
51 goto out;
52 }
53 m = s.st_mode;
54 if (!S_ISDIR(m))
55 continue;
56 ret = func(entry->d_name, private_data);
57 if (ret < 0)
58 goto out;
59 }
60 ret = 1;
61 out:
62 closedir(dir);
63 return ret;
64 }
65 /**
66 * Wrapper for chdir(2).
67 *
68 * \param path The specified directory.
69 *
70 * \return Standard.
71 */
72 int dss_chdir(const char *path)
73 {
74 if (chdir(path) >= 0)
75 return 1;
76 return -ERRNO_TO_DSS_ERROR(errno);
77 }
78
79 /**
80 * Set a file descriptor to non-blocking mode.
81 *
82 * \param fd The file descriptor.
83 *
84 * \return Standard.
85 */
86 __must_check int mark_fd_nonblocking(int fd)
87 {
88 int flags = fcntl(fd, F_GETFL);
89 if (flags < 0)
90 return -ERRNO_TO_DSS_ERROR(errno);
91 flags = fcntl(fd, F_SETFL, ((long)flags) | O_NONBLOCK);
92 if (flags < 0)
93 return -ERRNO_TO_DSS_ERROR(errno);
94 return 1;
95 }
96
97 /**
98 * dss' wrapper for select(2).
99 *
100 * It calls select(2) (with no exceptfds) and starts over if select() was
101 * interrupted by a signal.
102 *
103 * \param n The highest-numbered descriptor in any of the two sets, plus 1.
104 * \param readfds fds that should be checked for readability.
105 * \param writefds fds that should be checked for writablility.
106 * \param timeout_tv upper bound on the amount of time elapsed before select()
107 * returns.
108 *
109 * \return The return value of the underlying select() call on success, the
110 * negative system error code on errors.
111 *
112 * All arguments are passed verbatim to select(2).
113 * \sa select(2) select_tut(2).
114 */
115 int dss_select(int n, fd_set *readfds, fd_set *writefds,
116 struct timeval *timeout_tv)
117 {
118 int ret, err;
119 do {
120 ret = select(n, readfds, writefds, NULL, timeout_tv);
121 err = errno;
122 } while (ret < 0 && err == EINTR);
123 if (ret < 0)
124 return -ERRNO_TO_DSS_ERROR(errno);
125 return ret;
126 }