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NAME

Lintian::Util - Lintian utility functions

SYNOPSIS

 use Lintian::Util;

DESCRIPTION

This module contains a number of utility subs that are nice to have, but on their own did not warrant their own module.

Most subs are imported only on request.

VARIABLES

$PKGNAME_REGEX

Regular expression that matches valid package names. The expression is not anchored and does not enforce any "boundary" characters.

$PKGREPACK_REGEX

Regular expression that matches "repacked" package names. The expression is not anchored and does not enforce any "boundary" characters. It should only be applied to the upstream portion (see #931846).

$PKGVERSION_REGEX

Regular expression that matches valid package versions. The expression is not anchored and does not enforce any "boundary" characters.

FUNCTIONS

drain_pipe(FD)

Reads and discards any remaining contents from FD, which is assumed to be a pipe. This is mostly done to avoid having the "write"-end die with a SIGPIPE due to a "broken pipe" (which can happen if you just close the pipe).

May cause an exception if there are issues reading from the pipe.

Caveat: This will block until the pipe is closed from the "write"-end, so only use it with pipes where the "write"-end will eventually close their end by themselves (or something else will make them close it).

get_file_digest(ALGO, FILE)

Creates an ALGO digest object that is seeded with the contents of FILE. If you just want the hex digest, please use "get_file_checksum(ALGO, FILE)" instead.

ALGO can be 'md5' or shaX, where X is any number supported by Digest::SHA (e.g. 'sha256').

This sub is a convenience wrapper around Digest::{MD5,SHA}.

get_file_checksum(ALGO, FILE)

Returns a hexadecimal string of the message digest checksum generated by the algorithm ALGO on FILE.

ALGO can be 'md5' or shaX, where X is any number supported by Digest::SHA (e.g. 'sha256').

This sub is a convenience wrapper around Digest::{MD5,SHA}.

do_fork()

Overrides fork to reset signal handlers etc. in the child.

perm2oct(PERM)

Translates PERM to an octal permission. PERM should be a string describing the permissions as done by tar t or ls -l. That is, it should be a string like "-rw-r--r--".

If the string does not appear to be a valid permission, it will cause a trappable error.

Examples:

 # Good
 perm2oct('-rw-r--r--') == 0644
 perm2oct('-rwxr-xr-x') == 0755

 # Bad
 perm2oct('broken')      # too short to be recognised
 perm2oct('-resurunet')  # contains unknown permissions
run_cmd([OPTS, ]COMMAND[, ARGS...])

Executes the given COMMAND with the (optional) arguments ARGS and returns the status code as one would see it from a shell script. Shell features cannot be used.

OPTS, if given, is a hash reference with zero or more of the following key-value pairs:

chdir

The child process with chdir to the given directory before executing the command.

in

The STDIN of the child process will be reopened and read from the filename denoted by the value of this key. By default, STDIN will reopened to read from /dev/null.

out

The STDOUT of the child process will be reopened and write to filename denoted by the value of this key. By default, STDOUT is discarded.

update-env-vars

Each key/value pair defined in the hashref associated with update-env-vars will be updated in the child processes's environment. If a value is undef, then the corresponding environment variable will be removed (if set). Otherwise, the environment value will be set to that value.

copy_dir (ARGS)

Convenient way of calling cp -a ARGS.

human_bytes(SIZE)
open_gz (FILE)

Opens a handle that reads from the GZip compressed FILE.

On failure, this sub emits a trappable error.

Note: The handle may be a pipe from an external processes.

locate_helper_tool(TOOLNAME)

Given the name of a helper tool, returns the path to it. The tool must be available in the "helpers" subdir of one of the "lintian root" directories used by Lintian.

The tool name should follow the same rules as check names. Particularly, third-party checks should namespace their tools in the same way they namespace their checks. E.g. "python/some-helper".

If the tool cannot be found, this sub will cause a trappable error.

check_path (CMD)

Returns 1 if CMD can be found in PATH (i.e. $ENV{PATH}) and is executable. Otherwise, the function return 0.

drop_relative_prefix(STRING)

Remove an initial ./ from STRING, if present

signal_number2name(NUM)

Given a number, returns the name of the signal (without leading "SIG"). Example:

    signal_number2name(2) eq 'INT'
normalize_pkg_path(PATH)

Normalize PATH by removing superfluous path segments. PATH is assumed to be relative the package root. Note that the result will never start nor end with a slash, even if PATH does.

As the name suggests, this is a path "normalization" rather than a true path resolution (for that use Cwd::realpath). Particularly, it assumes none of the path segments are symlinks.

normalize_pkg_path will return q{} (i.e. the empty string) if PATH is normalized to the root dir and undef if the path cannot be normalized without escaping the package root.

normalize_link_target(CURDIR, LINK_TARGET)

Normalize the path obtained by following a link with LINK_TARGET as its target from CURDIR as the current directory. CURDIR is assumed to be relative to the package root. Note that the result will never start nor end with a slash, even if CURDIR or DEST does.

normalize_pkg_path will return q{} (i.e. the empty string) if the target is the root dir and undef if the path cannot be normalized without escaping the package root.

CAVEAT: This function is not always sufficient to test if it is safe to open a given symlink. Use is_ancestor_of for that. If you must use this function, remember to check that the target is not a symlink (or if it is, that it can be resolved safely).

is_ancestor_of(PARENTDIR, PATH)

Returns true if and only if PATH is PARENTDIR or a path stored somewhere within PARENTDIR (or its subdirs).

This function will resolve the paths; any failure to resolve the path will cause a trappable error.

read_md5sums
unescape_md5sum_filename

SEE ALSO

lintian(1)

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