cygcheck

cygcheck [-c|-d|-f|-l|-o|-p|-s] [package|file|DLL|version...] [OPTION...]

-c [package...]
    Checks the installed packages. Can verify specific packages for integrity and dependencies, or all packages if none are specified.

-d [executable...]
    Lists all DLL (Dynamic Link Library) dependencies for one or more specified executables. Essential for debugging runtime errors.

-f [file...]
    Finds which installed package a given file belongs to. Useful for resolving file ownership and troubleshooting missing files.

-l [package...]
    Lists all files contained within one or more specified installed packages. Provides an inventory of package contents.

-o [file...]
    Shows the owner package for a specified file. Similar to -f, often used for identifying orphaned files.

-p [file_pattern...]
    Searches for files within the available (not necessarily installed) Cygwin packages that match a given pattern.

-s
    Displays comprehensive system information related to the Cygwin installation, including version, paths, and mounted filesystems.

-v
    Enables verbose output, providing more detailed information during checks, helpful for in-depth debugging.

-r root_dir
    Specifies an alternative Cygwin root directory to check, useful for managing multiple Cygwin installations.

--dll-path
    Shows the DLL search path used by Cygwin executables, aiding in understanding DLL resolution.

--check-installed-dependencies
    Verifies DLLs for all installed packages, performing a comprehensive system health check for all components.

--help
    Displays a help message with command usage and options, then exits.

--version
    Displays version information for cygcheck, then exits.

The cygcheck command is a vital diagnostic utility specific to the Cygwin environment, which provides a Unix-like compatibility layer on Microsoft Windows. Unlike traditional Linux commands, cygcheck operates within Cygwin to manage and inspect its unique package system and runtime dependencies. Its primary function is to help users and administrators troubleshoot issues related to the Cygwin installation, such as missing files, conflicting DLLs, or corrupted packages.

Users frequently employ cygcheck to list installed packages, verify the integrity of specific packages, and identify which files belong to which package. A crucial feature is its ability to analyze executable files and report their DLL (Dynamic Link Library) dependencies, making it indispensable for resolving "DLL not found" errors or problems arising from mismatched DLL versions. It can also display comprehensive system information pertinent to the Cygwin setup, including mounted filesystems and environment variables.

By providing detailed insights into the Cygwin environment's health and package relationships, cygcheck empowers users to self-diagnose and resolve common problems, ensuring a stable and functional Unix-like experience on Windows.

The cygcheck command is exclusively designed for the Cygwin environment running on Microsoft Windows and is not a native Linux command. Its functionality relies heavily on the Cygwin package management system and its internal database, meaning it is not applicable outside of a Cygwin installation. Users should be aware that running checks, especially comprehensive dependency checks, can be time-consuming and produce extensive output, which may require careful parsing.

It is crucial to understand that cygcheck operates within the specific context of the Cygwin environment. Its primary purpose is to diagnose and report on the health and configuration of a Cygwin installation, including its intricate management of Unix-like filesystems, DLLs, and package dependencies on a Windows host. It is not a general-purpose Linux system tool and has no direct applicability outside of Cygwin.

One of cygcheck's most valuable uses is as a first-line troubleshooting tool for Cygwin users. When applications fail to launch due to missing or incorrect DLLs, or when packages behave unexpectedly, cygcheck can quickly pinpoint the underlying issue, such as an incomplete installation, a conflicting file, or a missing dependency, thereby greatly simplifying the debugging process and reducing downtime.

cygcheck was developed as an integral part of the Cygwin project, which began in the mid-1990s as a way to bring Unix-like functionality to Windows. As the Cygwin environment grew in complexity, particularly with its reliance on dynamically linked libraries (DLLs) and a sophisticated package management system, the need for a robust diagnostic tool became evident. cygcheck was created to fill this role, evolving over time to address common installation, dependency, and package integrity issues unique to bridging the Unix and Windows operating paradigms. It has remained a cornerstone utility for Cygwin users and developers for decades.

ldd(1), apt(8), dnf(8), yum(8), dpkg(1), rpm(8), cygpath(1), setup-x86_64.exe (Cygwin installer)