{
"schema_version": "1.0",
"command": "chmod",
"variant": "gnu",
"match": {
"probe": {
"args": ["--version"],
"expect": "success",
"output_contains": "GNU coreutils"
}
},
"mode": "authoritative",
"confidence": "verified",
"provenance": {
"platform": "linux",
"tool_version": "9.7",
"package": "coreutils",
"source": "help",
"checked_on": "2026-07-27",
"command": "docker run --rm debian@sha256:328d16499860ae6cb9b345e2e4cebca08c2a36e4f7278482c7bd1f39d71e5bfd chmod --help",
"environment": "debian@sha256:328d16499860ae6cb9b345e2e4cebca08c2a36e4f7278482c7bd1f39d71e5bfd",
"notes": "Acceptance by the binary is NOT usable as evidence for chmod: its symbolic mode grammar shares the '-x' shape with its options, so 'chmod -w file' succeeds while '-w' is a MODE operand. Only options listed in --help are recorded. -H/-L/-P are deliberately NOT marked as conflicting here even though the BSD variant documents them as overriding each other: GNU's help makes no such statement and 'chmod -R -L -P 755 f' exits 0, so the BSD wording was not carried across. GNU has no ACL options; that surface is BSD-only. conflicts_with was extended in a later pass, after the field's definition widened to cover override groups as well as diagnosed errors: apexe's input is a JSON object, which carries no ordering, so for a last-one-wins group which flag actually wins is decided by the order the caller happened to write the keys in. Every pair added then was run in BOTH orders against the reference build recorded above, and only pairs whose outcome depends on that order, or where one side is silently discarded, were added."
},
"description": "Change the mode of each FILE to MODE. With --reference, change the mode of each FILE to that of RFILE. MODE may be given as an octal number or as a symbolic mode string.",
"flags": [
{ "short": "-c", "long": "--changes", "type": "boolean", "conflicts_with": ["-v"], "description": "Like --verbose but report only when a change is actually made." },
{ "short": "-f", "long": "--silent", "type": "boolean", "description": "Suppress most error messages. Also spelled --quiet." },
{ "long": "--quiet", "type": "boolean", "description": "Suppress most error messages. Synonym for --silent." },
{ "short": "-v", "long": "--verbose", "type": "boolean", "conflicts_with": ["-c"], "description": "Output a diagnostic for every file processed." },
{ "long": "--dereference", "type": "boolean", "conflicts_with": ["--no-dereference", "-h"], "description": "Affect the referent of each symbolic link, rather than the symbolic link itself." },
{ "short": "-h", "long": "--no-dereference", "type": "boolean", "conflicts_with": ["--dereference"], "description": "Affect each symbolic link, rather than the referent it points to." },
{ "long": "--no-preserve-root", "type": "boolean", "conflicts_with": ["--preserve-root"], "description": "Do not treat '/' specially. This is the default." },
{ "long": "--preserve-root", "type": "boolean", "conflicts_with": ["--no-preserve-root"], "description": "Fail to operate recursively on '/'." },
{ "long": "--reference", "type": "path", "value_name": "RFILE", "description": "Use RFILE's mode instead of specifying a MODE value. RFILE is always dereferenced if it is a symbolic link." },
{ "short": "-R", "long": "--recursive", "type": "boolean", "description": "Change files and directories recursively." },
{ "short": "-H", "type": "boolean", "conflicts_with": ["-L", "-P"], "description": "If a command line argument is a symbolic link to a directory, traverse it. Modifies how a hierarchy is traversed when -R is also specified." },
{ "short": "-L", "type": "boolean", "conflicts_with": ["-H", "-P"], "description": "Traverse every symbolic link to a directory encountered. Modifies how a hierarchy is traversed when -R is also specified." },
{ "short": "-P", "type": "boolean", "conflicts_with": ["-H", "-L"], "description": "Do not traverse any symbolic links. This is the default. Modifies how a hierarchy is traversed when -R is also specified." },
{ "long": "--help", "type": "boolean", "description": "Display help and exit." },
{ "long": "--version", "type": "boolean", "description": "Output version information and exit." }
],
"positional_args": [
{ "name": "mode", "type": "string", "description": "The new mode, as an octal number or a symbolic mode string. Omitted when --reference is used." },
{ "name": "file", "type": "path", "required": true, "variadic": true, "description": "Files whose mode is to be changed." }
],
"annotations": {
"readonly": false,
"destructive": true,
"idempotent": true,
"requires_approval": true
}
}