Update cheatsheets

tldr/float

@@ -0,0 +1,27 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# float
+
+> Declare floating point variable(s).
+> Equivalent to `typeset -E` except that options irrelevant to floating point numbers are not permitted.
+> See also: `typeset`, `declare`.
+> More information: <https://manned.org/zshbuiltins>.
+
+- Declare a floating point variable:
+
+`float {{variable_name}}`
+
+- Declare a floating point variable while assigning its value:
+
+`float {{variable_name}}={{value}}`
+
+- Declare multiple floating point variables:
+
+`float {{var1=value1 var2=value2 ...}}`
+
+- Display defined variables:
+
+`float`

tldr/linux/journalctl

@@ -9,18 +9,14 @@ source: https://github.com/tldr-pages/tldr.git
 > See also: `dmesg`.
 > More information: <https://www.freedesktop.org/software/systemd/man/latest/journalctl.html>.
 
-- Show all messages with priority level 3 (errors) from this boot:
-
-`journalctl {{[-b|--boot]}} {{[-p|--priority]}} 3`
-
-- Delete journal logs which are older than 2 days:
-
-`journalctl --vacuum-time 2d`
-
-- Show only the last `n` lines and follow new messages (like `tail -f` for traditional syslog):
+- Show the latest `n` lines and follow new messages (like `tail --follow` for traditional syslog):
 
 `journalctl {{[-n|--lines]}} {{n}} {{[-f|--follow]}}`
 
+- Show all messages with priority level 3 (errors) from the boot before last shutdown:
+
+`journalctl {{[-b|--boot]}} -1 {{[-p|--priority]}} 3`
+
 - Show all messages by a specific unit:
 
 `journalctl {{[-u|--unit]}} {{unit}}`
@@ -31,7 +27,7 @@ source: https://github.com/tldr-pages/tldr.git
 
 - Filter messages within a time range (either timestamp or placeholders like "yesterday"):
 
-`journalctl {{[-S|--since]}} {{now|today|yesterday|tomorrow}} {{[-U|--until]}} "{{YYYY-MM-DD HH:MM:SS}}"`
+`journalctl {{[-S|--since]}} {{now|today|yesterday|tomorrow|...}} {{[-U|--until]}} "{{YYYY-MM-DD HH:MM:SS}}"`
 
 - Show all messages by a specific process:
 
@@ -40,3 +36,7 @@ source: https://github.com/tldr-pages/tldr.git
 - Show all messages by a specific executable:
 
 `journalctl {{path/to/executable}}`
+
+- Delete journal logs which are older than 2 days:
+
+`journalctl --vacuum-time 2d`

tldr/linux/opkg

@@ -22,7 +22,7 @@ source: https://github.com/tldr-pages/tldr.git
 
 - Upgrade one or more specific package(s):
 
-`opkg upgrade {{package(s)}}`
+`opkg upgrade {{package1 package2 ...}}`
 
 - Display information for a specific package:
 

tldr/windows/ping

@@ -0,0 +1,38 @@
+---
+syntax: markdown
+tags: [tldr, windows]
+source: https://github.com/tldr-pages/tldr.git
+---
+# ping
+
+> Send ICMP ECHO_REQUEST packets to network hosts.
+> Unlike Unix-like systems, Windows `ping` sends only 4 packets by default.
+> More information: <https://learn.microsoft.com/windows-server/administration/windows-commands/ping>.
+
+- Ping a host 4 times:
+
+`ping {{host}}`
+
+- Ping a host a specific number of times:
+
+`ping -n {{count}} {{host}}`
+
+- Ping a host continuously (until stopped with `<Ctrl c>`):
+
+`ping -t {{host}}`
+
+- Set the timeout in milliseconds to wait for each reply:
+
+`ping -w {{milliseconds}} {{host}}`
+
+- Set the buffer size of the ping packet in bytes:
+
+`ping -l {{bytes}} {{host}}`
+
+- Ping a host using a specific source IP address:
+
+`ping -S {{source_ip}} {{host}}`
+
+- Resolve address to hostname:
+
+`ping -a {{host}}`

tldr/x-ping

@@ -24,6 +24,6 @@ source: https://github.com/tldr-pages/tldr.git
 
 `ping {{host}} | x ping vis {{[-m|--heatmap]}}`
 
-- Show help:
+- Display help:
 
 `x ping {{[-h|--help]}}`