summaryrefslogtreecommitdiffstats
path: root/lib/path.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/path.c')
-rw-r--r--lib/path.c1226
1 files changed, 1226 insertions, 0 deletions
diff --git a/lib/path.c b/lib/path.c
new file mode 100644
index 0000000..48fb505
--- /dev/null
+++ b/lib/path.c
@@ -0,0 +1,1226 @@
+/*
+ * Simple functions to access files. Paths can be globally prefixed to read
+ * data from an alternative source (e.g. a /proc dump for regression tests).
+ *
+ * The paths is possible to format by printf-like way for functions with "f"
+ * postfix in the name (e.g. readf, openf, ... ul_path_readf_u64()).
+ *
+ * The ul_path_read_* API is possible to use without path_cxt handler. In this
+ * case is not possible to use global prefix and printf-like formatting.
+ *
+ * No copyright is claimed. This code is in the public domain; do with
+ * it what you wish.
+ *
+ * Written by Karel Zak <kzak@redhat.com> [February 2018]
+ */
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <errno.h>
+
+#include "c.h"
+#include "fileutils.h"
+#include "all-io.h"
+#include "path.h"
+#include "debug.h"
+
+/*
+ * Debug stuff (based on include/debug.h)
+ */
+static UL_DEBUG_DEFINE_MASK(ulpath);
+UL_DEBUG_DEFINE_MASKNAMES(ulpath) = UL_DEBUG_EMPTY_MASKNAMES;
+
+#define ULPATH_DEBUG_INIT (1 << 1)
+#define ULPATH_DEBUG_CXT (1 << 2)
+
+#define DBG(m, x) __UL_DBG(ulpath, ULPATH_DEBUG_, m, x)
+#define ON_DBG(m, x) __UL_DBG_CALL(ulpath, ULPATH_DEBUG_, m, x)
+
+#define UL_DEBUG_CURRENT_MASK UL_DEBUG_MASK(ulpath)
+#include "debugobj.h"
+
+void ul_path_init_debug(void)
+{
+ if (ulpath_debug_mask)
+ return;
+ __UL_INIT_DEBUG_FROM_ENV(ulpath, ULPATH_DEBUG_, 0, ULPATH_DEBUG);
+}
+
+struct path_cxt *ul_new_path(const char *dir, ...)
+{
+ struct path_cxt *pc = calloc(1, sizeof(*pc));
+
+ if (!pc)
+ return NULL;
+
+ DBG(CXT, ul_debugobj(pc, "alloc"));
+
+ pc->refcount = 1;
+ pc->dir_fd = -1;
+
+ if (dir) {
+ int rc;
+ va_list ap;
+
+ va_start(ap, dir);
+ rc = vasprintf(&pc->dir_path, dir, ap);
+ va_end(ap);
+
+ if (rc < 0 || !pc->dir_path)
+ goto fail;
+ }
+ return pc;
+fail:
+ ul_unref_path(pc);
+ return NULL;
+}
+
+void ul_ref_path(struct path_cxt *pc)
+{
+ if (pc)
+ pc->refcount++;
+}
+
+void ul_unref_path(struct path_cxt *pc)
+{
+ if (!pc)
+ return;
+
+ pc->refcount--;
+
+ if (pc->refcount <= 0) {
+ DBG(CXT, ul_debugobj(pc, "dealloc"));
+ if (pc->dialect)
+ pc->free_dialect(pc);
+ if (pc->dir_fd >= 0)
+ close(pc->dir_fd);
+ free(pc->dir_path);
+ free(pc->prefix);
+ free(pc);
+ }
+}
+
+int ul_path_set_prefix(struct path_cxt *pc, const char *prefix)
+{
+ char *p = NULL;
+
+ assert(pc->dir_fd < 0);
+
+ if (prefix) {
+ p = strdup(prefix);
+ if (!p)
+ return -ENOMEM;
+ }
+
+ free(pc->prefix);
+ pc->prefix = p;
+ DBG(CXT, ul_debugobj(pc, "new prefix: '%s'", p));
+ return 0;
+}
+
+const char *ul_path_get_prefix(struct path_cxt *pc)
+{
+ return pc ? pc->prefix : NULL;
+}
+
+int ul_path_set_dir(struct path_cxt *pc, const char *dir)
+{
+ char *p = NULL;
+
+ if (dir) {
+ p = strdup(dir);
+ if (!p)
+ return -ENOMEM;
+ }
+
+ if (pc->dir_fd >= 0) {
+ close(pc->dir_fd);
+ pc->dir_fd = -1;
+ }
+
+ free(pc->dir_path);
+ pc->dir_path = p;
+ DBG(CXT, ul_debugobj(pc, "new dir: '%s'", p));
+ return 0;
+}
+
+const char *ul_path_get_dir(struct path_cxt *pc)
+{
+ return pc ? pc->dir_path : NULL;
+}
+
+int ul_path_set_dialect(struct path_cxt *pc, void *data, void free_data(struct path_cxt *))
+{
+ pc->dialect = data;
+ pc->free_dialect = free_data;
+ DBG(CXT, ul_debugobj(pc, "(re)set dialect"));
+ return 0;
+}
+
+void *ul_path_get_dialect(struct path_cxt *pc)
+{
+ return pc ? pc->dialect : NULL;
+}
+
+int ul_path_set_enoent_redirect(struct path_cxt *pc, int (*func)(struct path_cxt *, const char *, int *))
+{
+ pc->redirect_on_enoent = func;
+ return 0;
+}
+
+static const char *get_absdir(struct path_cxt *pc)
+{
+ int rc;
+ const char *dirpath;
+
+ if (!pc->prefix)
+ return pc->dir_path;
+
+ dirpath = pc->dir_path;
+ if (!dirpath)
+ return pc->prefix;
+ if (*dirpath == '/')
+ dirpath++;
+
+ rc = snprintf(pc->path_buffer, sizeof(pc->path_buffer), "%s/%s", pc->prefix, dirpath);
+ if (rc < 0)
+ return NULL;
+ if ((size_t)rc >= sizeof(pc->path_buffer)) {
+ errno = ENAMETOOLONG;
+ return NULL;
+ }
+
+ return pc->path_buffer;
+}
+
+int ul_path_get_dirfd(struct path_cxt *pc)
+{
+ assert(pc);
+ assert(pc->dir_path);
+
+ if (pc->dir_fd < 0) {
+ const char *path = get_absdir(pc);
+ if (!path)
+ return -errno;
+
+ DBG(CXT, ul_debugobj(pc, "opening dir: '%s'", path));
+ pc->dir_fd = open(path, O_RDONLY|O_CLOEXEC);
+ }
+
+ return pc->dir_fd;
+}
+
+static const char *ul_path_mkpath(struct path_cxt *pc, const char *path, va_list ap)
+{
+ int rc = vsnprintf(pc->path_buffer, sizeof(pc->path_buffer), path, ap);
+
+ if (rc < 0)
+ return NULL;
+
+ if ((size_t)rc >= sizeof(pc->path_buffer)) {
+ errno = ENAMETOOLONG;
+ return NULL;
+ }
+
+ return pc->path_buffer;
+}
+
+char *ul_path_get_abspath(struct path_cxt *pc, char *buf, size_t bufsz, const char *path, ...)
+{
+ if (path) {
+ int rc;
+ va_list ap;
+ const char *tail = NULL, *dirpath = pc->dir_path;
+
+ va_start(ap, path);
+ tail = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (dirpath && *dirpath == '/')
+ dirpath++;
+ if (tail && *tail == '/')
+ tail++;
+
+ rc = snprintf(buf, bufsz, "%s/%s/%s",
+ pc->prefix ? pc->prefix : "",
+ dirpath ? dirpath : "",
+ tail ? tail : "");
+
+ if ((size_t)rc >= bufsz) {
+ errno = ENAMETOOLONG;
+ return NULL;
+ }
+ } else {
+ const char *tmp = get_absdir(pc);
+
+ if (!tmp)
+ return NULL;
+ strncpy(buf, tmp, bufsz);
+ buf[bufsz - 1] = '\0';
+ }
+
+ return buf;
+}
+
+
+int ul_path_access(struct path_cxt *pc, int mode, const char *path)
+{
+ int dir, rc;
+
+ dir = ul_path_get_dirfd(pc);
+ if (dir < 0)
+ return dir;
+
+ DBG(CXT, ul_debugobj(pc, "access: '%s'", path));
+ rc = faccessat(dir, path, mode, 0);
+
+ if (rc && errno == ENOENT
+ && pc->redirect_on_enoent
+ && pc->redirect_on_enoent(pc, path, &dir) == 0)
+ rc = faccessat(dir, path, mode, 0);
+ return rc;
+}
+
+int ul_path_accessf(struct path_cxt *pc, int mode, const char *path, ...)
+{
+ va_list ap;
+ const char *p;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ return ul_path_access(pc, mode, p);
+}
+
+int ul_path_open(struct path_cxt *pc, int flags, const char *path)
+{
+ int fd;
+
+ if (!pc) {
+ fd = open(path, flags);
+ DBG(CXT, ul_debug("opening '%s'", path));
+ } else {
+ int fdx;
+ int dir = ul_path_get_dirfd(pc);
+ if (dir < 0)
+ return dir;
+
+ fdx = fd = openat(dir, path, flags);
+
+ if (fd < 0 && errno == ENOENT
+ && pc->redirect_on_enoent
+ && pc->redirect_on_enoent(pc, path, &dir) == 0)
+ fd = openat(dir, path, flags);
+
+ DBG(CXT, ul_debugobj(pc, "opening '%s'%s", path, fdx != fd ? " [redirected]" : ""));
+ }
+ return fd;
+}
+
+int ul_path_vopenf(struct path_cxt *pc, int flags, const char *path, va_list ap)
+{
+ const char *p;
+
+ p = ul_path_mkpath(pc, path, ap);
+ if (!p)
+ return -errno;
+
+ return ul_path_open(pc, flags, p);
+}
+
+int ul_path_openf(struct path_cxt *pc, int flags, const char *path, ...)
+{
+ va_list ap;
+ int rc;
+
+ va_start(ap, path);
+ rc = ul_path_vopenf(pc, flags, path, ap);
+ va_end(ap);
+
+ return rc;
+}
+
+/*
+ * Maybe stupid, but good enough ;-)
+ */
+static int mode2flags(const char *mode)
+{
+ int flags = 0;
+ const char *p;
+
+ for (p = mode; p && *p; p++) {
+ if (*p == 'r' && *(p + 1) == '+')
+ flags |= O_RDWR;
+ else if (*p == 'r')
+ flags |= O_RDONLY;
+
+ else if (*p == 'w' && *(p + 1) == '+')
+ flags |= O_RDWR | O_TRUNC;
+ else if (*p == 'w')
+ flags |= O_WRONLY | O_TRUNC;
+
+ else if (*p == 'a' && *(p + 1) == '+')
+ flags |= O_RDWR | O_APPEND;
+ else if (*p == 'a')
+ flags |= O_WRONLY | O_APPEND;
+#ifdef O_CLOEXEC
+ else if (*p == *UL_CLOEXECSTR)
+ flags |= O_CLOEXEC;
+#endif
+ }
+
+ return flags;
+}
+
+FILE *ul_path_fopen(struct path_cxt *pc, const char *mode, const char *path)
+{
+ int flags = mode2flags(mode);
+ int fd = ul_path_open(pc, flags, path);
+
+ if (fd < 0)
+ return NULL;
+
+ return fdopen(fd, mode);
+}
+
+
+FILE *ul_path_vfopenf(struct path_cxt *pc, const char *mode, const char *path, va_list ap)
+{
+ const char *p;
+
+ p = ul_path_mkpath(pc, path, ap);
+ if (!p)
+ return NULL;
+
+ return ul_path_fopen(pc, mode, p);
+}
+
+FILE *ul_path_fopenf(struct path_cxt *pc, const char *mode, const char *path, ...)
+{
+ FILE *f;
+ va_list ap;
+
+ va_start(ap, path);
+ f = ul_path_vfopenf(pc, mode, path, ap);
+ va_end(ap);
+
+ return f;
+}
+
+/*
+ * Open directory @path in read-onl mode. If the path is NULL then duplicate FD
+ * to the directory addressed by @pc.
+ */
+DIR *ul_path_opendir(struct path_cxt *pc, const char *path)
+{
+ DIR *dir;
+ int fd = -1;
+
+ if (path)
+ fd = ul_path_open(pc, O_RDONLY|O_CLOEXEC, path);
+ else if (pc->dir_path) {
+ DBG(CXT, ul_debugobj(pc, "duplicate dir path"));
+ fd = dup_fd_cloexec(ul_path_get_dirfd(pc), STDERR_FILENO + 1);
+ }
+
+ if (fd < 0)
+ return NULL;
+
+ dir = fdopendir(fd);
+ if (!dir) {
+ close(fd);
+ return NULL;
+ }
+ if (!path)
+ rewinddir(dir);
+ return dir;
+}
+
+
+/*
+ * Open directory @path in read-onl mode. If the path is NULL then duplicate FD
+ * to the directory addressed by @pc.
+ */
+DIR *ul_path_vopendirf(struct path_cxt *pc, const char *path, va_list ap)
+{
+ const char *p;
+
+ p = ul_path_mkpath(pc, path, ap);
+ if (!p)
+ return NULL;
+
+ return ul_path_opendir(pc, p);
+}
+
+/*
+ * Open directory @path in read-onl mode. If the path is NULL then duplicate FD
+ * to the directory addressed by @pc.
+ */
+DIR *ul_path_opendirf(struct path_cxt *pc, const char *path, ...)
+{
+ va_list ap;
+ DIR *dir;
+
+ va_start(ap, path);
+ dir = ul_path_vopendirf(pc, path, ap);
+ va_end(ap);
+
+ return dir;
+}
+
+/*
+ * If @path is NULL then readlink is called on @pc directory.
+ */
+ssize_t ul_path_readlink(struct path_cxt *pc, char *buf, size_t bufsiz, const char *path)
+{
+ int dirfd;
+
+ if (!path) {
+ const char *p = get_absdir(pc);
+ if (!p)
+ return -errno;
+ return readlink(p, buf, bufsiz);
+ }
+
+ dirfd = ul_path_get_dirfd(pc);
+ if (dirfd < 0)
+ return dirfd;
+
+ return readlinkat(dirfd, path, buf, bufsiz);
+}
+
+/*
+ * If @path is NULL then readlink is called on @pc directory.
+ */
+ssize_t ul_path_readlinkf(struct path_cxt *pc, char *buf, size_t bufsiz, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -errno;
+
+ return ul_path_readlink(pc, buf, bufsiz, p);
+}
+
+int ul_path_read(struct path_cxt *pc, char *buf, size_t len, const char *path)
+{
+ int rc, errsv;
+ int fd;
+
+ fd = ul_path_open(pc, O_RDONLY|O_CLOEXEC, path);
+ if (fd < 0)
+ return -errno;
+
+ DBG(CXT, ul_debug(" reading '%s'", path));
+ rc = read_all(fd, buf, len);
+
+ errsv = errno;
+ close(fd);
+ errno = errsv;
+ return rc;
+}
+
+int ul_path_vreadf(struct path_cxt *pc, char *buf, size_t len, const char *path, va_list ap)
+{
+ const char *p;
+
+ p = ul_path_mkpath(pc, path, ap);
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read(pc, buf, len, p);
+}
+
+int ul_path_readf(struct path_cxt *pc, char *buf, size_t len, const char *path, ...)
+{
+ va_list ap;
+ int rc;
+
+ va_start(ap, path);
+ rc = ul_path_vreadf(pc, buf, len, path, ap);
+ va_end(ap);
+
+ return rc;
+}
+
+
+/*
+ * Returns newly allocated buffer with data from file. Maximal size is BUFSIZ
+ * (send patch if you need something bigger;-)
+ *
+ * Returns size of the string!
+ */
+int ul_path_read_string(struct path_cxt *pc, char **str, const char *path)
+{
+ char buf[BUFSIZ];
+ int rc;
+
+ *str = NULL;
+
+ rc = ul_path_read(pc, buf, sizeof(buf) - 1, path);
+ if (rc < 0 || !str)
+ return rc;;
+
+ /* Remove tailing newline (usuall in sysfs) */
+ if (rc > 0 && *(buf + rc - 1) == '\n')
+ --rc;
+
+ buf[rc] = '\0';
+ *str = strdup(buf);
+ if (!*str)
+ rc = -ENOMEM;
+
+ return rc;
+}
+
+int ul_path_readf_string(struct path_cxt *pc, char **str, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read_string(pc, str, p);
+}
+
+int ul_path_read_buffer(struct path_cxt *pc, char *buf, size_t bufsz, const char *path)
+{
+ int rc = ul_path_read(pc, buf, bufsz - 1, path);
+ if (rc < 0)
+ return rc;;
+
+ /* Remove tailing newline (usuall in sysfs) */
+ if (rc > 0 && *(buf + rc - 1) == '\n')
+ --rc;
+
+ buf[rc] = '\0';
+ return rc;
+}
+
+int ul_path_readf_buffer(struct path_cxt *pc, char *buf, size_t bufsz, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read_buffer(pc, buf, bufsz, p);
+}
+
+int ul_path_scanf(struct path_cxt *pc, const char *path, const char *fmt, ...)
+{
+ FILE *f;
+ va_list fmt_ap;
+ int rc;
+
+ f = ul_path_fopen(pc, "r" UL_CLOEXECSTR, path);
+ if (!f)
+ return -EINVAL;
+
+ DBG(CXT, ul_debug(" fscanf [%s] '%s'", fmt, path));
+
+ va_start(fmt_ap, fmt);
+ rc = vfscanf(f, fmt, fmt_ap);
+ va_end(fmt_ap);
+
+ fclose(f);
+ return rc;
+}
+
+int ul_path_scanff(struct path_cxt *pc, const char *path, va_list ap, const char *fmt, ...)
+{
+ FILE *f;
+ va_list fmt_ap;
+ int rc;
+
+ f = ul_path_vfopenf(pc, "r" UL_CLOEXECSTR, path, ap);
+ if (!f)
+ return -EINVAL;
+
+ va_start(fmt_ap, fmt);
+ rc = vfscanf(f, fmt, fmt_ap);
+ va_end(fmt_ap);
+
+ fclose(f);
+ return rc;
+}
+
+
+int ul_path_read_s64(struct path_cxt *pc, int64_t *res, const char *path)
+{
+ int64_t x = 0;
+ int rc;
+
+ rc = ul_path_scanf(pc, path, "%"SCNd64, &x);
+ if (rc != 1)
+ return -1;
+ if (res)
+ *res = x;
+ return 0;
+}
+
+int ul_path_readf_s64(struct path_cxt *pc, int64_t *res, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;;
+
+ return ul_path_read_s64(pc, res, p);
+}
+
+int ul_path_read_u64(struct path_cxt *pc, uint64_t *res, const char *path)
+{
+ uint64_t x = 0;
+ int rc;
+
+ rc = ul_path_scanf(pc, path, "%"SCNu64, &x);
+ if (rc != 1)
+ return -1;
+ if (res)
+ *res = x;
+ return 0;
+}
+
+int ul_path_readf_u64(struct path_cxt *pc, uint64_t *res, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read_u64(pc, res, p);
+}
+
+int ul_path_read_s32(struct path_cxt *pc, int *res, const char *path)
+{
+ int rc, x = 0;
+
+ rc = ul_path_scanf(pc, path, "%d", &x);
+ if (rc != 1)
+ return -1;
+ if (res)
+ *res = x;
+ return 0;
+}
+
+int ul_path_readf_s32(struct path_cxt *pc, int *res, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read_s32(pc, res, p);
+}
+
+int ul_path_read_u32(struct path_cxt *pc, unsigned int *res, const char *path)
+{
+ int rc;
+ unsigned int x;
+
+ rc = ul_path_scanf(pc, path, "%u", &x);
+ if (rc != 1)
+ return -1;
+ if (res)
+ *res = x;
+ return 0;
+}
+
+int ul_path_readf_u32(struct path_cxt *pc, unsigned int *res, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read_u32(pc, res, p);
+}
+
+int ul_path_read_majmin(struct path_cxt *pc, dev_t *res, const char *path)
+{
+ int rc, maj, min;
+
+ rc = ul_path_scanf(pc, path, "%d:%d", &maj, &min);
+ if (rc != 2)
+ return -1;
+ if (res)
+ *res = makedev(maj, min);
+ return 0;
+}
+
+int ul_path_readf_majmin(struct path_cxt *pc, dev_t *res, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_read_majmin(pc, res, p);
+}
+
+int ul_path_write_string(struct path_cxt *pc, const char *str, const char *path)
+{
+ int rc, errsv;
+ int fd;
+
+ fd = ul_path_open(pc, O_WRONLY|O_CLOEXEC, path);
+ if (fd < 0)
+ return -errno;
+
+ rc = write_all(fd, str, strlen(str));
+
+ errsv = errno;
+ close(fd);
+ errno = errsv;
+ return rc;
+}
+
+int ul_path_writef_string(struct path_cxt *pc, const char *str, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_write_string(pc, str, p);
+}
+
+int ul_path_write_s64(struct path_cxt *pc, int64_t num, const char *path)
+{
+ char buf[sizeof(stringify_value(LLONG_MAX))];
+ int rc, errsv;
+ int fd, len;
+
+ fd = ul_path_open(pc, O_WRONLY|O_CLOEXEC, path);
+ if (fd < 0)
+ return -errno;
+
+ len = snprintf(buf, sizeof(buf), "%" PRId64, num);
+ if (len < 0 || (size_t) len >= sizeof(buf))
+ rc = len < 0 ? -errno : -E2BIG;
+ else
+ rc = write_all(fd, buf, len);
+
+ errsv = errno;
+ close(fd);
+ errno = errsv;
+ return rc;
+}
+
+int ul_path_write_u64(struct path_cxt *pc, uint64_t num, const char *path)
+{
+ char buf[sizeof(stringify_value(ULLONG_MAX))];
+ int rc, errsv;
+ int fd, len;
+
+ fd = ul_path_open(pc, O_WRONLY|O_CLOEXEC, path);
+ if (fd < 0)
+ return -errno;
+
+ len = snprintf(buf, sizeof(buf), "%" PRIu64, num);
+ if (len < 0 || (size_t) len >= sizeof(buf))
+ rc = len < 0 ? -errno : -E2BIG;
+ else
+ rc = write_all(fd, buf, len);
+
+ errsv = errno;
+ close(fd);
+ errno = errsv;
+ return rc;
+}
+
+int ul_path_writef_u64(struct path_cxt *pc, uint64_t num, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return -EINVAL;
+
+ return ul_path_write_u64(pc, num, p);
+
+}
+
+static struct dirent *xreaddir(DIR *dp)
+{
+ struct dirent *d;
+
+ while ((d = readdir(dp))) {
+ if (!strcmp(d->d_name, ".") ||
+ !strcmp(d->d_name, ".."))
+ continue;
+
+ /* blacklist here? */
+ break;
+ }
+ return d;
+}
+
+int ul_path_count_dirents(struct path_cxt *pc, const char *path)
+{
+ DIR *dir;
+ int r = 0;
+
+ dir = ul_path_opendir(pc, path);
+ if (!dir)
+ return 0;
+
+ while (xreaddir(dir)) r++;
+
+ closedir(dir);
+ return r;
+}
+
+int ul_path_countf_dirents(struct path_cxt *pc, const char *path, ...)
+{
+ const char *p;
+ va_list ap;
+
+ va_start(ap, path);
+ p = ul_path_mkpath(pc, path, ap);
+ va_end(ap);
+
+ if (!p)
+ return 0;
+
+ return ul_path_count_dirents(pc, p);
+}
+
+/*
+ * Like fopen() but, @path is always prefixed by @prefix. This function is
+ * useful in case when ul_path_* API is overkill.
+ */
+FILE *ul_prefix_fopen(const char *prefix, const char *path, const char *mode)
+{
+ char buf[PATH_MAX];
+
+ if (!path)
+ return NULL;
+ if (!prefix)
+ return fopen(path, mode);
+ if (*path == '/')
+ path++;
+
+ snprintf(buf, sizeof(buf), "%s/%s", prefix, path);
+ return fopen(buf, mode);
+}
+
+#ifdef HAVE_CPU_SET_T
+static int ul_path_cpuparse(struct path_cxt *pc, cpu_set_t **set, int maxcpus, int islist, const char *path, va_list ap)
+{
+ FILE *f;
+ size_t setsize, len = maxcpus * 7;
+ char buf[len];
+
+ *set = NULL;
+
+ f = ul_path_vfopenf(pc, "r" UL_CLOEXECSTR, path, ap);
+ if (!f)
+ return -errno;
+
+ if (!fgets(buf, len, f))
+ return -errno;
+ fclose(f);
+
+ len = strlen(buf);
+ if (buf[len - 1] == '\n')
+ buf[len - 1] = '\0';
+
+ *set = cpuset_alloc(maxcpus, &setsize, NULL);
+ if (!*set)
+ return -ENOMEM;
+
+ if (islist) {
+ if (cpulist_parse(buf, *set, setsize, 0)) {
+ cpuset_free(*set);
+ return -EINVAL;
+ }
+ } else {
+ if (cpumask_parse(buf, *set, setsize)) {
+ cpuset_free(*set);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+int ul_path_readf_cpuset(struct path_cxt *pc, cpu_set_t **set, int maxcpus, const char *path, ...)
+{
+ va_list ap;
+ int rc = 0;
+
+ va_start(ap, path);
+ rc = ul_path_cpuparse(pc, set, maxcpus, 0, path, ap);
+ va_end(ap);
+
+ return rc;
+}
+
+int ul_path_readf_cpulist(struct path_cxt *pc, cpu_set_t **set, int maxcpus, const char *path, ...)
+{
+ va_list ap;
+ int rc = 0;
+
+ va_start(ap, path);
+ rc = ul_path_cpuparse(pc, set, maxcpus, 1, path, ap);
+ va_end(ap);
+
+ return rc;
+}
+
+#endif /* HAVE_CPU_SET_T */
+
+
+#ifdef TEST_PROGRAM_PATH
+#include <getopt.h>
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+ fprintf(stdout, " %s [options] <dir> <command>\n\n", program_invocation_short_name);
+ fputs(" -p, --prefix <dir> redirect hardcoded paths to <dir>\n", stdout);
+
+ fputs(" Commands:\n", stdout);
+ fputs(" read-u64 <file> read uint64_t from file\n", stdout);
+ fputs(" read-s64 <file> read int64_t from file\n", stdout);
+ fputs(" read-u32 <file> read uint32_t from file\n", stdout);
+ fputs(" read-s32 <file> read int32_t from file\n", stdout);
+ fputs(" read-string <file> read string from file\n", stdout);
+ fputs(" read-majmin <file> read devno from file\n", stdout);
+ fputs(" read-link <file> read symlink\n", stdout);
+ fputs(" write-string <file> <str> write string from file\n", stdout);
+ fputs(" write-u64 <file> <str> write uint64_t from file\n", stdout);
+
+ exit(EXIT_SUCCESS);
+}
+
+int main(int argc, char *argv[])
+{
+ int c;
+ const char *prefix = NULL, *dir, *file, *command;
+ struct path_cxt *pc = NULL;
+
+ static const struct option longopts[] = {
+ { "prefix", 1, NULL, 'p' },
+ { "help", 0, NULL, 'h' },
+ { NULL, 0, NULL, 0 },
+ };
+
+ while((c = getopt_long(argc, argv, "p:h", longopts, NULL)) != -1) {
+ switch(c) {
+ case 'p':
+ prefix = optarg;
+ break;
+ case 'h':
+ usage();
+ break;
+ default:
+ err(EXIT_FAILURE, "try --help");
+ }
+ }
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<dir> not defined");
+ dir = argv[optind++];
+
+ ul_path_init_debug();
+
+ pc = ul_new_path(dir);
+ if (!pc)
+ err(EXIT_FAILURE, "failed to initialize path context");
+ if (prefix)
+ ul_path_set_prefix(pc, prefix);
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<command> not defined");
+ command = argv[optind++];
+
+ if (strcmp(command, "read-u32") == 0) {
+ uint32_t res;
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_read_u32(pc, &res, file) != 0)
+ err(EXIT_FAILURE, "read u64 failed");
+ printf("read: %s: %u\n", file, res);
+
+ if (ul_path_readf_u32(pc, &res, "%s", file) != 0)
+ err(EXIT_FAILURE, "readf u64 failed");
+ printf("readf: %s: %u\n", file, res);
+
+ } else if (strcmp(command, "read-s32") == 0) {
+ int32_t res;
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_read_s32(pc, &res, file) != 0)
+ err(EXIT_FAILURE, "read u64 failed");
+ printf("read: %s: %d\n", file, res);
+
+ if (ul_path_readf_s32(pc, &res, "%s", file) != 0)
+ err(EXIT_FAILURE, "readf u64 failed");
+ printf("readf: %s: %d\n", file, res);
+
+ } else if (strcmp(command, "read-u64") == 0) {
+ uint64_t res;
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_read_u64(pc, &res, file) != 0)
+ err(EXIT_FAILURE, "read u64 failed");
+ printf("read: %s: %" PRIu64 "\n", file, res);
+
+ if (ul_path_readf_u64(pc, &res, "%s", file) != 0)
+ err(EXIT_FAILURE, "readf u64 failed");
+ printf("readf: %s: %" PRIu64 "\n", file, res);
+
+ } else if (strcmp(command, "read-s64") == 0) {
+ int64_t res;
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_read_s64(pc, &res, file) != 0)
+ err(EXIT_FAILURE, "read u64 failed");
+ printf("read: %s: %" PRIu64 "\n", file, res);
+
+ if (ul_path_readf_s64(pc, &res, "%s", file) != 0)
+ err(EXIT_FAILURE, "readf u64 failed");
+ printf("readf: %s: %" PRIu64 "\n", file, res);
+
+ } else if (strcmp(command, "read-majmin") == 0) {
+ dev_t res;
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_read_majmin(pc, &res, file) != 0)
+ err(EXIT_FAILURE, "read maj:min failed");
+ printf("read: %s: %d\n", file, (int) res);
+
+ if (ul_path_readf_majmin(pc, &res, "%s", file) != 0)
+ err(EXIT_FAILURE, "readf maj:min failed");
+ printf("readf: %s: %d\n", file, (int) res);
+
+ } else if (strcmp(command, "read-string") == 0) {
+ char *res;
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_read_string(pc, &res, file) < 0)
+ err(EXIT_FAILURE, "read string failed");
+ printf("read: %s: %s\n", file, res);
+
+ if (ul_path_readf_string(pc, &res, "%s", file) < 0)
+ err(EXIT_FAILURE, "readf string failed");
+ printf("readf: %s: %s\n", file, res);
+
+ } else if (strcmp(command, "read-link") == 0) {
+ char res[PATH_MAX];
+
+ if (optind == argc)
+ errx(EXIT_FAILURE, "<file> not defined");
+ file = argv[optind++];
+
+ if (ul_path_readlink(pc, res, sizeof(res), file) < 0)
+ err(EXIT_FAILURE, "read symlink failed");
+ printf("read: %s: %s\n", file, res);
+
+ if (ul_path_readlinkf(pc, res, sizeof(res), "%s", file) < 0)
+ err(EXIT_FAILURE, "readf symlink failed");
+ printf("readf: %s: %s\n", file, res);
+
+ } else if (strcmp(command, "write-string") == 0) {
+ char *str;
+
+ if (optind + 1 == argc)
+ errx(EXIT_FAILURE, "<file> <string> not defined");
+ file = argv[optind++];
+ str = argv[optind++];
+
+ if (ul_path_write_string(pc, str, file) != 0)
+ err(EXIT_FAILURE, "write string failed");
+ if (ul_path_writef_string(pc, str, "%s", file) != 0)
+ err(EXIT_FAILURE, "writef string failed");
+
+ } else if (strcmp(command, "write-u64") == 0) {
+ uint64_t num;
+
+ if (optind + 1 == argc)
+ errx(EXIT_FAILURE, "<file> <num> not defined");
+ file = argv[optind++];
+ num = strtoumax(argv[optind++], NULL, 0);
+
+ if (ul_path_write_u64(pc, num, file) != 0)
+ err(EXIT_FAILURE, "write u64 failed");
+ if (ul_path_writef_u64(pc, num, "%s", file) != 0)
+ err(EXIT_FAILURE, "writef u64 failed");
+ }
+
+ ul_unref_path(pc);
+ return EXIT_SUCCESS;
+}
+#endif /* TEST_PROGRAM_PATH */
+