1 files changed, 92 insertions, 0 deletions
diff --git a/errors.go b/errors.go
new file mode 100644
index 0000000..7da8395
--- /dev/null
+++ b/errors.go
@@ -0,0 +1,92 @@
+package prep
+
+// Gemini's excellent at this sorta research. Not much else though
+
+// This file defines a set of conventional exit codes for command-line applications,
+// based on the BSD `sysexits.h` standard and common GNU/Linux practices.
+// Using these constants makes the program's exit behavior clear and consistent.
+
+// ExitCode represents a program's exit status code.
+type ExitCode int
+
+const (
+	// --- Standard Success/Failure ---
+
+	// ExitSuccess indicates that the program completed its task without errors.
+	ExitSuccess ExitCode = 0
+
+	// ExitFailure is a generic, catch-all code for "something went wrong."
+	// It should be used if no other more specific code applies.
+	ExitFailure ExitCode = 1
+
+	// --- Errors based on BSD sysexits.h ---
+
+	// ExitUsage indicates that the user provided invalid command-line arguments or flags.
+	// (Standard: EX_USAGE)
+	ExitUsage ExitCode = 64
+
+	// ExitDataErr indicates that the input data was incorrect or malformed.
+	// (e.g., a corrupt configuration file).
+	// (Standard: EX_DATAERR)
+	ExitDataErr ExitCode = 65
+
+	// ExitNoInput indicates that an input file was not found or could not be read.
+	// (Standard: EX_NOINPUT)
+	ExitNoInput ExitCode = 66
+
+	// ExitNoUser indicates that a specified user did not exist.
+	// (Standard: EX_NOUSER)
+	ExitNoUser ExitCode = 67
+
+	// ExitNoHost indicates that a specified host did not exist.
+	// (Standard: EX_NOHOST)
+	ExitNoHost ExitCode = 68
+
+	// ExitUnavailable indicates that a required service is unavailable.
+	// (Standard: EX_UNAVAILABLE)
+	ExitUnavailable ExitCode = 69
+
+	// ExitSoftware indicates an internal software error. This is for unexpected
+	// conditions and bugs ("this should never happen").
+	// (Standard: EX_SOFTWARE)
+	ExitSoftware ExitCode = 70
+
+	// ExitOSErr indicates an operating system error, such as a failed system call.
+	// (e.g., fork failed, couldn't create a directory).
+	// (Standard: EX_OSERR)
+	ExitOSErr ExitCode = 71
+
+	// ExitOSFile indicates a critical OS file is missing or corrupt.
+	// (e.g., /etc/passwd).
+	// (Standard: EX_OSFILE)
+	ExitOSFile ExitCode = 72
+
+	// ExitCantCreat indicates that a user-specified output file could not be created.
+	// (Standard: EX_CANTCREAT)
+	ExitCantCreat ExitCode = 73
+
+	// ExitIOErr indicates an error occurred during an I/O operation.
+	// (Standard: EX_IOERR)
+	ExitIOErr ExitCode = 74
+
+	// ExitTempFail indicates a temporary failure. The user is invited to retry.
+	// (Standard: EX_TEMPFAIL)
+	ExitTempFail ExitCode = 75
+
+	// ExitProtocol indicates a protocol error during network communication.
+	// (Standard: EX_PROTOCOL)
+	ExitProtocol ExitCode = 76
+
+	// ExitNoPerm indicates that the user does not have sufficient permissions.
+	// This is for filesystem permissions, not for authentication issues.
+	// (Standard: EX_NOPERM)
+	ExitNoPerm ExitCode = 77
+
+	// ExitConfig indicates that something is wrong in a configuration file.
+	// (Standard: EX_CONFIG)
+	ExitConfig ExitCode = 78
+)
+
+// Note: Exit codes 126, 127, and >128 are reserved for the shell to indicate
+// specific execution failures (command not executable, command not found, or
+// termination by a signal) and should not be used by applications.