diff options
-rw-r--r-- | c_pgms/INFO | 2 | ||||
-rw-r--r-- | c_pgms/truncate_write.c | 156 |
2 files changed, 158 insertions, 0 deletions
diff --git a/c_pgms/INFO b/c_pgms/INFO index b755c79..a73a6df 100644 --- a/c_pgms/INFO +++ b/c_pgms/INFO @@ -17,3 +17,5 @@ c_pgms/new-ps-perf(new-fs-perf.c) -----> fs-perf test program modified. Now the =============================================== c_pgms/ping_pong.c (ping_pong.c) -------> ping_pong program modified. Now the time duration for which ping_pong should execute can be given as an argument. By default it executed for 600 seconds. + +c_pgms/truncate_write.c (trucate_write.c) -----> it truncates a file to the size specified (default is 5GB, and creates and truncates if the file does not exist), writes some data to some offset. diff --git a/c_pgms/truncate_write.c b/c_pgms/truncate_write.c new file mode 100644 index 0000000..d6dcce9 --- /dev/null +++ b/c_pgms/truncate_write.c @@ -0,0 +1,156 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/stat.h> +#include <sys/types.h> + +#define UNIT_KB 1024ULL +#define UNIT_MB UNIT_KB*1024ULL +#define UNIT_GB UNIT_MB*1024ULL +#define UNIT_TB UNIT_GB*1024ULL +#define UNIT_PB UNIT_TB*1024ULL + +#define UNIT_KB_STRING "KB" +#define UNIT_MB_STRING "MB" +#define UNIT_GB_STRING "GB" +#define UNIT_TB_STRING "TB" +#define UNIT_PB_STRING "PB" + +int +string2bytesize (const char *str, unsigned long long *n) +{ + unsigned long long value = 0ULL; + char *tail = NULL; + int old_errno = 0; + const char *s = NULL; + + if (str == NULL || n == NULL) + { + errno = EINVAL; + return -1; + } + + for (s = str; *s != '\0'; s++) + { + if (isspace (*s)) + { + continue; + } + if (*s == '-') + { + return -1; + } + break; + } + + old_errno = errno; + errno = 0; + value = strtoull (str, &tail, 10); + + if (errno == ERANGE || errno == EINVAL) + { + return -1; + } + + if (errno == 0) + { + errno = old_errno; + } + + if (tail[0] != '\0') + { + if (strcasecmp (tail, UNIT_KB_STRING) == 0) + { + value *= UNIT_KB; + } + else if (strcasecmp (tail, UNIT_MB_STRING) == 0) + { + value *= UNIT_MB; + } + else if (strcasecmp (tail, UNIT_GB_STRING) == 0) + { + value *= UNIT_GB; + } + else if (strcasecmp (tail, UNIT_TB_STRING) == 0) + { + value *= UNIT_TB; + } + else if (strcasecmp (tail, UNIT_PB_STRING) == 0) + { + value *= UNIT_PB; + } + + else + { + return -1; + } + } + + *n = value; + + return 0; +} + +int main (int argc, char *argv[]) +{ + int ret = -1; + int fd = -1; + char *buf = "This is a string"; + char *filename = NULL; + unsigned long long size = 0; + + if (argc < 2) { + fprintf (stderr, "Usage:./a.out <filename>\n"); + return 2; + } + + filename = argv[1]; + + fd = open (filename, O_CREAT|O_RDWR, 0644); + if (fd == -1) { + fprintf (stderr, "OPEN: cannot open the file fff. (%s)", + strerror (errno)); + return 2; + } + + if (argc < 3) + size = 5 * UNIT_GB; + else + string2bytesize (argv[2], &size); + + ret = ftruncate (fd, size); + if (ret == -1) { + fprintf (stderr, "TRUNCATE: cannot truncate the file %s. (%s)", + filename, strerror (errno)); + goto out; + } + + printf ("File got truncated tp %llu bytes. Sleeping for 22 seconds. " + "Kill the brick.....\n", size); + + sleep (22); + + ret = lseek (fd, 1048576, SEEK_SET); + if (ret == -1) { + fprintf (stderr, "LSEEK: cannot seek to the offset file fff. " + "(%s)", strerror (errno)); + goto out; + } + + ret = write (fd, buf, strlen (buf)); + if (ret == -1) { + fprintf (stderr, "WRITE: cannot write to the file fff. (%s)", + strerror (errno)); + goto out; + } + + ret = 0; +out: + if (fd) + close (fd); + + return ret; +} |