BLOG

stat – display file or file system status

Jeffrin December 28, 2009 No Comments operating system filesystem, stat, statistics

GNU Command stat -f / $stat -f / File: “/” ID: bc427fdafb7b0541 Namelen: 255 Type: ext2/ext3 Block size: 4096 Fundamental block size: 4096 Blocks: Total: 18864769 Free: 16209639 Available: 15251363 Inodes: Total: 4792320 Free: 4684854 $ Explanation Display file or file system status. Related Source Code Exposition static bool do_statfs (char const *filename, bool terse, char const *format) { STRUCT_STATVFS statfsbuf; if (STATFS (filename, &statfsbuf) != 0) { error (0, errno, _(“cannot read file system information for %s”), quote (filename)); …

vmstat – Report virtual memory statistics

Jeffrin December 28, 2009 operating system vmstat

A UNIX Command . vmstat -m Cache Num Total Size Pages fat_inode_cache 23 23 688 23 fat_cache 102 102 40 102 isofs_inode_cache 0 0 1006 12 udf_inode_cache 23 23 712 23 fuse_request 0 0 632 25 fuse_inode 0 0 768 21 dm_crypt_io 0 0 152 26 kcopyd_job 0 0 368 22 dm_uevent 0 0 2608 12 dm_rq_target_io 0 0 400 20 ext3_inode_cache 11017 12882 824 19 ext3_xattr 0 0 88 46 journal_handle 170 170 24 170 journal_head 36 36 112 …

ypdomainname – show or set the system’s NIS/YP domain name

Jeffrin December 27, 2009 No Comments computer networks domain, YP

ABOUT NIS The Network Information Service, or NIS (originally called Yellow Pages or YP), is a client–server directory service protocol for distributing system configuration data such as user and host names between computers on a computer network. Sun Microsystems developed the NIS; the technology is licensed to virtually all other Unix vendors. Because British Telecom PLC owned the name “Yellow Pages” as a registered trademark in the United Kingdom for its paper-based, commercial telephone directory, Sun changed the name of …

backtrace for iceweasel related hangup

Jeffrin December 26, 2009 Debug Method Development

(gdb) bt #0 0x00007fc68928b99d in pthread_join (threadid=1404900385100136, thread_return=0x0) at pthread_join.c:89 #16 0x00007fc68773d8e8 in XRE_main (argc=, argv=, aAppData=) at nsAppRunner.cpp:3331 #17 0x00000000004024df in main (argc=1, argv=0x7fffaa9352c8) at nsXULStub.cpp:493

getopt – parse command options

Jeffrin December 25, 2009 operating system getopt

commandline session $getopt hello — $getopt hello how are you ? — how are you 1 c h $getopt hello hello are you ? — hello are you 1 c h $getopt hello hello are yours ? — hello are yours 1 c h $getopt hello hello are yours what ? — hello are yours what 1 c h $getopt hello hello are yours what — hello are yours what $getopt hello hello are yours what ! — hello are …

compilation error. libjingle

Jeffrin December 24, 2009 No Comments Uncategorized

commandline session ../../talk/base/messagequeue.h: In constructor ‘talk_base::Message::Message()’: ../../talk/base/messagequeue.h:121: error: ‘memset’ was not declared in this scope i have failed to fix it until now.it did not compile sucessfully. a typical source is available here The document may have broken link.

head – output the first part of files

Jeffrin December 23, 2009 No Comments Uncategorized

commandline session $sudo head /var/log/syslog Jan 5 20:10:05 debian syslogd 1.5.0#6.1: restart. Jan 5 20:10:05 debian anacron[1056]: Job `cron.daily’ terminated Jan 5 20:10:05 debian anacron[1056]: Normal exit (1 job run) Jan 5 20:12:14 debian acpid: client connected from 1055[0:0] Jan 5 20:12:14 debian acpid: 1 client rule loaded Jan 5 20:12:14 debian acpid: client connected from 1055[0:0] Jan 5 20:12:14 debian acpid: 1 client rule loaded Jan 5 20:13:03 debian acpid: client 1055[0:0] has disconnected Jan 5 20:13:03 debian acpid: …

hexdump, hd — ASCII, decimal, hexadecimal, octal dump

Jeffrin December 16, 2009 No Comments operating system hexdump

$cat version.c #include #include int main(int argc, char **argv) { printf(“MySQL client version: %sn”, mysql_get_client_info()); } Commandline Session $hexdump version.c 0000000 6923 636e 756c 10064 3c20 796d 675f 6f6c 0000010 6162 2e6c 3e68 230a 6e69 6c63 6475 20100 0000020 6d3c 7379 6c71 682e 0a3e 690a 746e 6d20 0000030 6961 286e 6e69 2074 7261 6367 202c 6863 0000040 7261 2a20 612a 6772 2976 7b0a 200a 7020 0000050 6972 746e 2866 4d22 5379 4c51 6320 696c 0000060 6e100 2074 10076 7372 6f69 …

Hacking with the “groups” GNU command

Jeffrin December 8, 2009 operating system groups

20.4 `groups’: Print group names a user is in ============================================= `groups’ prints the names of the primary and any supplementary groups for each given USERNAME, or the current process if no names are given. If more than one name is given, the name of each user is printed before the list of that user’s groups and the user name is separated from the group list by a colon. Synopsis: groups [USERNAME]… The group lists are equivalent to the output of …

true – do nothing, successfully. false – do nothing, unsuccessfully

Jeffrin November 29, 2009 No Comments operating system

GNU command $true $echo $? 0 $false $echo $? 1 $ Explanation true – do nothing, successfully exit with a status code indicating success. false – do nothing, unsuccessfully exit with a status code indicating failure. Related Source Code Exposition int main (int argc, char **argv) { if (argc == 2) { initialize_main (&argc, &argv); set_program_name (argv[0]); setlocale (LC_ALL, “”); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); atexit (close_stdout); if (STREQ (argv[1], “–help”)) usage (EXIT_STATUS); if (STREQ (argv[1], “–version”)) version_etc (stdout, PROGRAM_NAME, …