{"id":6620,"date":"2012-01-10T16:05:13","date_gmt":"2012-01-10T16:05:13","guid":{"rendered":"http:\/\/www.beautifulwork.org\/?p=6620"},"modified":"2012-01-10T16:05:13","modified_gmt":"2012-01-10T16:05:13","slug":"sysctl-interface","status":"publish","type":"post","link":"https:\/\/www.trueangle.org\/index.php\/2012\/01\/10\/sysctl-interface\/","title":{"rendered":"What is sysctl in some Unix-like Operating systems ?"},"content":{"rendered":"

ABOUT sysctl<\/u><\/p>\n

\nsysctl is a software utility of some Unix-like operating systems that reads and modifies the attributes of the system kernel such as its version number, maximum limits, and security settings. It is available both as a system call for compiled programs, and an administrator command for interactive use and scripting. Linux additionally exposes sysctl as a virtual file system.\n<\/pre>\n
\nRELATED SHELL EXPOSURE<\/u>
\n[bash]
\n$pwd
\n\/proc\/sys\/kernel
\n$cat hung_task_timeout_secs
\n120
\n$sudo sysctl kernel.hung_task_timeout_secs 121
\n[sudo] password for jeffrin:
\nkernel.hung_task_timeout_secs = 120
\nsysctl: cannot stat \/proc\/sys\/121: No such file or directory
\n$sudo sysctl kernel.hung_task_timeout_secs="121"
\nkernel.hung_task_timeout_secs = 121
\n$cat hung_task_timeout_secs
\n121
\n$sudo sysctl kernel.hung_task_timeout_secs="120"
\nkernel.hung_task_timeout_secs = 120
\n$cat hung_task_timeout_secs
\n120
\n$<\/p>\n
[\/bash]<\/p>\n
[bash collapse=”true”]
\nroot@debian:~# cd \/proc\/sys
\nroot@debian:\/proc\/sys#  grep . kernel\/*
\nkernel\/acct:4\t2\t30
\nkernel\/acpi_video_flags:0
\nkernel\/auto_msgmni:1
\nkernel\/blk_iopoll:1
\nkernel\/bootloader_type:114
\nkernel\/bootloader_version:2
\nkernel\/cad_pid:1
\nkernel\/compat-log:1
\nkernel\/core_pattern:core
\nkernel\/core_pipe_limit:0
\nkernel\/core_uses_pid:0
\nkernel\/ctrl-alt-del:0
\nkernel\/dmesg_restrict:0
\nkernel\/domainname:(none)
\nkernel\/ftrace_dump_on_oops:0
\nkernel\/hostname:debian
\nkernel\/hung_task_check_count:4194304
\nkernel\/hung_task_panic:0
\nkernel\/hung_task_timeout_secs:120
\nkernel\/hung_task_warnings:10
\nkernel\/io_delay_type:0
\ngrep: kernel\/keys: Invalid argument
\nkernel\/kptr_restrict:0
\nkernel\/kstack_depth_to_print:12
\nkernel\/max_lock_depth:1024
\nkernel\/modprobe:\/sbin\/modprobe
\nkernel\/modules_disabled:0
\nkernel\/msgmax:8192
\nkernel\/msgmnb:16384
\nkernel\/msgmni:3893
\nkernel\/ngroups_max:100536
\nkernel\/nmi_watchdog:1
\nkernel\/osrelease:3.1.0-1-amd64
\nkernel\/ostype:Linux
\nkernel\/overflowgid:100534
\nkernel\/overflowuid:100534
\nkernel\/panic:0
\nkernel\/panic_on_io_nmi:0
\nkernel\/panic_on_oops:0
\nkernel\/panic_on_unrecovered_nmi:0
\nkernel\/perf_event_max_sample_rate:100000
\nkernel\/perf_event_mlock_kb:516
\nkernel\/perf_event_paranoid:1
\nkernel\/pid_max:32768
\nkernel\/poweroff_cmd:\/sbin\/poweroff
\nkernel\/print-fatal-signals:0
\nkernel\/printk:4\t4\t1\t7
\nkernel\/printk_delay:0
\nkernel\/printk_ratelimit:5
\nkernel\/printk_ratelimit_burst:10
\ngrep: kernel\/pty: Invalid argument
\ngrep: kernel\/random: Invalid argument
\nkernel\/randomize_va_space:2
\nkernel\/real-root-dev:0
\nkernel\/sched_autogroup_enabled:0
\nkernel\/sched_child_runs_first:0
\ngrep: kernel\/sched_domain: Invalid argument
\nkernel\/sched_latency_ns:6000000
\nkernel\/sched_migration_cost:500000
\nkernel\/sched_min_granularity_ns:750000
\nkernel\/sched_nr_migrate:32
\nkernel\/sched_rt_period_us:1000000
\nkernel\/sched_rt_runtime_us:950000
\nkernel\/sched_shares_window:10000000
\nkernel\/sched_time_avg:1000
\nkernel\/sched_tunable_scaling:1
\nkernel\/sched_wakeup_granularity_ns:1000000
\nkernel\/sem:250\t32000\t32\t128
\nkernel\/shmall:2097152
\nkernel\/shmmax:33554432
\nkernel\/shmmni:4096
\nkernel\/shm_rmid_forced:0
\nkernel\/softlockup_panic:0
\nkernel\/sysrq:438
\nkernel\/tainted:4097
\nkernel\/threads-max:30982
\nkernel\/timer_migration:1
\nkernel\/unknown_nmi_panic:0
\ngrep: kernel\/usermodehelper: Invalid argument
\nkernel\/version:#1 SMP Fri Dec 23 16:37:11 UTC 2011
\nkernel\/watchdog:1
\nkernel\/watchdog_thresh:10
\nroot@debian:\/proc\/sys#<\/p>\n
[\/bash]<\/p>\n
RELATED LINKS
\nhttps:\/\/en.wikipedia.org\/wiki\/Sysctl<\/a>
\nhttp:\/\/man7.org\/linux\/man-pages\/man8\/sysctl.8.html<\/a>
\nhttps:\/\/www.linuxjournal.com\/article\/2365<\/a>
\nhttps:\/\/dl.acm.org\/citation.cfm?id=326974<\/a>
\nhttps:\/\/www.kernel.org\/doc\/Documentation\/networking\/ip-sysctl.txt<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
ABOUT sysctl sysctl is a software utility of some Unix-like operating systems that reads and modifies the attributes of the system kernel such as its version number, maximum limits, and security settings. It is available both as a system call for compiled programs, and an administrator command for interactive use and scripting. Linux additionally exposes … <\/p>\n
Continue reading “What is sysctl in some Unix-like Operating systems ?”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[83],"tags":[1300,1530],"_links":{"self":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/6620"}],"collection":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/comments?post=6620"}],"version-history":[{"count":0,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/6620\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/media?parent=6620"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/categories?post=6620"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/tags?post=6620"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}