Merge pull request #270 from Stunkymonkey/mem-support

initial support of memory-usage for linux

diff --combined man/i3status.man
index 4ed54ac50de770e9654b8dc8d02f0c8dce3397cf,f8ce219fba6fd6fd4934debfa90fdfec93f39bd3..1d679a373742b25b6cad20920faebf5d41d0931f
--- 1/man/i3status.man
--- 2/man/i3status.man
+++ b/man/i3status.man
@@@ -1,7 -1,7 +1,7 @@@
  i3status(1)
  ===========
  Michael Stapelberg <michael@i3wm.org>
 -v2.11, January 2017
 +v2.12, May 2018
  
  == NAME
  
@@@ -55,6 -55,7 +55,7 @@@ order += "wireless wlan0
  order += "ethernet eth0"
  order += "battery 0"
  order += "cpu_temperature 0"
+ order += "memory"
  order += "load"
  order += "tztime local"
  order += "tztime berlin"
@@@ -113,6 -114,12 +114,12 @@@ cpu_temperature 0 
        path = "/sys/devices/platform/coretemp.0/temp1_input"
  }
  
+ memory {
+         format = "%used"
+         threshold_degraded = "10%"
+         format_degraded = "MEMORY: %free"
+ }
+ 
  disk "/" {
        format = "%free"
  }
@@@ -192,6 -199,7 +199,7 @@@ double-quote (""") characters need to b
  for generated content (e.g. wireless ESSID, time).
  
  *Example configuration*:
+ 
  -------------------------------------------------------------
  general {
      output_format = "xmobar"
@@@ -299,9 -307,7 +307,9 @@@ network interface found on the system (
  
  *Example order*: +wireless wlan0+
  
 -*Example format*: +W: (%quality at %essid, %bitrate / %frequency) %ip+
 +*Example format_up*: +W: (%quality at %essid, %bitrate / %frequency) %ip+
 +
 +*Example format_down*: +W: down+
  
  === Ethernet
  
@@@ -315,9 -321,7 +323,9 @@@ network interface found on the system (
  
  *Example order*: +ethernet eth0+
  
 -*Example format*: +E: %ip (%speed)+
 +*Example format_up*: +E: %ip (%speed)+
 +
 +*Example format_down*: +E: down+
  
  === Battery
  
@@@ -428,6 -432,45 +436,45 @@@ starting from %cpu0. This feature is cu
  
  *Example format_above_degraded_threshold*: +Warning above degraded threshold: %usage+
  
+ === Memory
+ 
+ Gets the memory usage from system on a Linux system from +/proc/meminfo+. Other
+ systems are currently not supported.
+ 
+ As format placeholders, +total+, +used+, +free+, +available+ and +shared+ are
+ available. These will print human readable values. It's also possible to prefix
+ the placeholders with +percentage_+ to get a value in percent.
+ 
+ It's possible to define a +threshold_degraded+ and a +threshold_critical+ to
+ color the status bar output in yellow or red, if the available memory falls
+ below the given threshold. Possible values of the threshold can be any integer,
+ suffixed with an iec symbol (+T+, +G+, +M+, +K+). Alternatively, the integer
+ can be suffixed by a percent sign, which then rets evaluated relatively to
+ total memory.
+ 
+ If the +format_degraded+ parameter is given and either the critical or the
+ degraded threshold applies, +format_degraded+ will get used as format string.
+ It acts equivalently to +format+.
+ 
+ As Linux' meminfo doesn't expose the overall memory in use, there are multiple
+ methods to distinguish the actually used memory. 
+ 
+ *Example used_memory_method*: +memavailable+ ("total memory" - "MemAvailable", matches gnome system monitor)
+ 
+ *Example used_memory_method*: +classical+ ("total memory" - "free" - "buffers" - "cache", matches gnome system monitor)
+ 
+ *Example order*: +memory+
+ 
+ *Example format*: +%free %available (%used) / %total+
+ 
+ *Example format*: +%percentage_used used, %percentage_free free, %percentage_shared shared+
+ 
+ *Example threshold_degraded*: +10%+
+ 
+ *Example threshold_critical*: +5%+
+ 
+ *Example format_degraded*: +Memory LOW: %free+
+ 
  === Load
  
  Gets the system load (number of processes waiting for CPU time in the last