x is - Value & Environment Validation#

x is is x-cmd's value validation tool for checking if values or environment states meet specific criteria. Supports batch checking multiple values, ideal for robust Shell scripting.

Prerequisites#

1. Load x-cmd before use: bash

   . ~/.x-cmd.root/X
   
   

Core Usage#

• Type Check: x is int 42 100 -5 / x is float 3.14
• Range Check: x is minmax 1 100 50 75
• Compare: x is eq "a" "a" / x is within "ok" pending success
• IP Check: x is ip 192.168.1.1
• File Age: x is newest target src/*.c / x is oldest cache.txt /tmp/*.tmp
• Variable Check: x is unset VAR1 VAR2
• Environment Detection: x is interactive / x is wsl / x is termux

Subcommands#

Type#

CommandDescriptionintInteger check, batch supportedfloatFloat check (must contain decimal point)positivePositive integer (≥0)negativeNegative integer (<0)minmaxRange check [MIN,MAX]

Compare#

CommandDescriptioneqMultiple values equalwithinFirst value in candidate listinColon-separated list member checkin-Dash-separated listin_Underscore-separated listin/Slash-separated listin|Pipe-separated list

Network#

CommandDescriptionipIPv4 address check

File#

CommandDescriptionnewestFile newer than others (glob supported)oldestFile older than others (glob supported)

Variable#

CommandDescriptionunsetVariable is unset

Environment#

CommandDescriptioninteractiveInteractive sessioninteractive_ttystdin is interactive TTYinteractiveshellShell is interactivereplREPL modestdout2ttystdout outputs to TTYwslWSL environmentcygwinCygwin environmentmsysMSYS/MinGW environmentgitbashGit Bash environmenttermuxTermux environmentishiSH environment

Suitability#

CommandDescriptionsuitable_pkgSuitable for package installationsuitable_advise_envSuitable for advise featuresuitable_advise_replSuitable for advise REPL

Practical Examples#

Batch Type Validation#

bash

x is int 1 2 3 4 5 && echo "All integers"
x is float 3.14 -2.5 .5 && echo "All floats"

Environment Conditional Branch#

bash

x is interactive && echo "Interactive session" || echo "Script mode"
x is wsl && echo "WSL environment" || echo "Not WSL"
x is termux && echo "Termux environment"

File Status Check#

bash

x is newest build.tar.gz src/*.c lib/*.h || echo "Rebuild needed"

Variable Cleanup Verification#

bash

x is unset TEMP_VAR1 TEMP_VAR2 && echo "Temp variables cleaned"

Script Pre-flight Check#

bash

x is suitable_pkg || { echo "Environment not suitable"; exit 1; }

Design Principles#

• Batch First: Check multiple values at once, all must pass
• Exit Code Semantics: 0 = success, 1 = failure, perfect for &&/ || chains
• Silent: Validation tool outputs nothing, only exit code indicates result

Get Help#

bash

x is --help