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Diffstat (limited to '')
| -rw-r--r-- | libblkid/path.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/libblkid/path.c b/libblkid/path.c new file mode 100644 index 000000000..4f955d91c --- /dev/null +++ b/libblkid/path.c @@ -0,0 +1,245 @@ +/* + * Simple functions to access files, paths maybe be globally prefixed by a + * global prefix to read data from alternative destination (e.g. /proc dump for + * regression tests). + * + * Taken from lscpu.c + * + * Copyright (C) 2008 Cai Qian <qcai@redhat.com> + * Copyright (C) 2008-2012 Karel Zak <kzak@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <stdarg.h> +#include <string.h> +#include <unistd.h> +#include <stdio.h> +#include <inttypes.h> +#include <errno.h> + +#include "all-io.h" +#include "path.h" +#include "nls.h" +#include "c.h" + +static size_t prefixlen; +static char pathbuf[PATH_MAX]; + +static const char * +path_vcreate(const char *path, va_list ap) +{ + if (prefixlen) + vsnprintf(pathbuf + prefixlen, + sizeof(pathbuf) - prefixlen, path, ap); + else + vsnprintf(pathbuf, sizeof(pathbuf), path, ap); + return pathbuf; +} + +static FILE * +path_vfopen(const char *mode, int exit_on_error, const char *path, va_list ap) +{ + FILE *f; + const char *p = path_vcreate(path, ap); + + f = fopen(p, mode); + if (!f && exit_on_error) + err(EXIT_FAILURE, _("cannot open %s"), p); + return f; +} + +static int +path_vopen(int flags, const char *path, va_list ap) +{ + int fd; + const char *p = path_vcreate(path, ap); + + fd = open(p, flags); + if (fd == -1) + err(EXIT_FAILURE, _("cannot open %s"), p); + return fd; +} + +FILE * +path_fopen(const char *mode, int exit_on_error, const char *path, ...) +{ + FILE *fd; + va_list ap; + + va_start(ap, path); + fd = path_vfopen(mode, exit_on_error, path, ap); + va_end(ap); + + return fd; +} + +void +path_read_str(char *result, size_t len, const char *path, ...) +{ + FILE *fd; + va_list ap; + + va_start(ap, path); + fd = path_vfopen("r", 1, path, ap); + va_end(ap); + + if (!fgets(result, len, fd)) + err(EXIT_FAILURE, _("failed to read: %s"), pathbuf); + fclose(fd); + + len = strlen(result); + if (result[len - 1] == '\n') + result[len - 1] = '\0'; +} + +int +path_read_s32(const char *path, ...) +{ + FILE *fd; + va_list ap; + int result; + + va_start(ap, path); + fd = path_vfopen("r", 1, path, ap); + va_end(ap); + + if (fscanf(fd, "%d", &result) != 1) { + if (ferror(fd)) + err(EXIT_FAILURE, _("failed to read: %s"), pathbuf); + else + errx(EXIT_FAILURE, _("parse error: %s"), pathbuf); + } + fclose(fd); + return result; +} + +uint64_t +path_read_u64(const char *path, ...) +{ + FILE *fd; + va_list ap; + uint64_t result; + + va_start(ap, path); + fd = path_vfopen("r", 1, path, ap); + va_end(ap); + + if (fscanf(fd, "%"SCNu64, &result) != 1) { + if (ferror(fd)) + err(EXIT_FAILURE, _("failed to read: %s"), pathbuf); + else + errx(EXIT_FAILURE, _("parse error: %s"), pathbuf); + } + fclose(fd); + return result; +} + +int +path_write_str(const char *str, const char *path, ...) +{ + int fd, result; + va_list ap; + + va_start(ap, path); + fd = path_vopen(O_WRONLY, path, ap); + va_end(ap); + result = write_all(fd, str, strlen(str)); + close(fd); + return result; +} + +int +path_exist(const char *path, ...) +{ + va_list ap; + const char *p; + + va_start(ap, path); + p = path_vcreate(path, ap); + va_end(ap); + + return access(p, F_OK) == 0; +} + +#ifdef HAVE_CPU_SET_T + +static cpu_set_t * +path_cpuparse(int maxcpus, int islist, const char *path, va_list ap) +{ + FILE *fd; + cpu_set_t *set; + size_t setsize, len = maxcpus * 7; + char buf[len]; + + fd = path_vfopen("r", 1, path, ap); + + if (!fgets(buf, len, fd)) + err(EXIT_FAILURE, _("failed to read: %s"), pathbuf); + fclose(fd); + + len = strlen(buf); + if (buf[len - 1] == '\n') + buf[len - 1] = '\0'; + + set = cpuset_alloc(maxcpus, &setsize, NULL); + if (!set) + err(EXIT_FAILURE, _("failed to callocate cpu set")); + + if (islist) { + if (cpulist_parse(buf, set, setsize, 0)) + errx(EXIT_FAILURE, _("failed to parse CPU list %s"), buf); + } else { + if (cpumask_parse(buf, set, setsize)) + errx(EXIT_FAILURE, _("failed to parse CPU mask %s"), buf); + } + return set; +} + +cpu_set_t * +path_read_cpuset(int maxcpus, const char *path, ...) +{ + va_list ap; + cpu_set_t *set; + + va_start(ap, path); + set = path_cpuparse(maxcpus, 0, path, ap); + va_end(ap); + + return set; +} + +cpu_set_t * +path_read_cpulist(int maxcpus, const char *path, ...) +{ + va_list ap; + cpu_set_t *set; + + va_start(ap, path); + set = path_cpuparse(maxcpus, 1, path, ap); + va_end(ap); + + return set; +} + +#endif /* HAVE_CPU_SET_T */ + +void +path_set_prefix(const char *prefix) +{ + prefixlen = strlen(prefix); + strncpy(pathbuf, prefix, sizeof(pathbuf)); + pathbuf[sizeof(pathbuf) - 1] = '\0'; +} |