$ pylint --reports=n main.py
Output:
No config file found, using default configuration
You will get the "No config file found, using default configuration" warning if you do not have a .pylintrc file in your home directory, or if you don't specify the pylint argument --rcfile=/path/to/pylintrc.
To suppress the message, on *nix:
$ touch ~/.pylintrc
found a pylintrc and using it, works. Posting it here in case anyone needs it. You can Modify it to suit your project.
# lint Python modules using external checkers.
#
# This is the main checker controling the other ones and the reports
# generation. It is itself both a raw checker and an astng checker in order
# to:
# * handle message activation / deactivation at the module level
# * handle some basic but necessary stats'data (number of classes, methods...)
#
[MASTER]
# Specify a configuration file.
#rcfile=
# Profiled execution.
profile=no
# Add to the black list. It should be a base name, not a
# path. You may set this option multiple times.
ignore=.svn
# Pickle collected data for later comparisons.
persistent=yes
# Set the cache size for astng objects.
cache-size=500
# List of plugins (as comma separated values of python modules names) to load,
# usually to register additional checkers.
load-plugins=
[MESSAGES CONTROL]
# Enable only checker(s) with the given id(s). This option conflict with the
# disable-checker option
#enable-checker=
# Enable all checker(s) except those with the given id(s). This option conflict
# with the disable-checker option
#disable-checker=
# Enable all messages in the listed categories.
#enable-msg-cat=
# Disable all messages in the listed categories.
#disable-msg-cat=
# Enable the message(s) with the given id(s).
#enable-msg=
# Disable the message(s) with the given id(s).
disable-msg=C0323,W0142,C0301,C0103,C0111,E0213,C0302,C0203,W0703,R0201
[REPORTS]
# set the output format. Available formats are text, parseable, colorized and
# html
output-format=colorized
# Include message's id in output
include-ids=yes
# Put messages in a separate file for each module / package specified on the
# command line instead of printing them on stdout. Reports (if any) will be
# written in a file name "pylint_global.[txt|html]".
files-output=no
# Tells wether to display a full report or only the messages
reports=yes
# Python expression which should return a note less than 10 (10 is the highest
# note).You have access to the variables errors warning, statement which
# respectivly contain the number of errors / warnings messages and the total
# number of statements analyzed. This is used by the global evaluation report
# (R0004).
evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)
# Add a comment according to your evaluation note. This is used by the global
# evaluation report (R0004).
comment=no
# Enable the report(s) with the given id(s).
#enable-report=
# Disable the report(s) with the given id(s).
#disable-report=
# checks for
# * unused variables / imports
# * undefined variables
# * redefinition of variable from builtins or from an outer scope
# * use of variable before assigment
#
[VARIABLES]
# Tells wether we should check for unused import in __init__ files.
init-import=no
# A regular expression matching names used for dummy variables (i.e. not used).
dummy-variables-rgx=_|dummy
# List of additional names supposed to be defined in builtins. Remember that
# you should avoid to define new builtins when possible.
additional-builtins=
# try to find bugs in the code using type inference
#
[TYPECHECK]
# Tells wether missing members accessed in mixin class should be ignored. A
# mixin class is detected if its name ends with "mixin" (case insensitive).
ignore-mixin-members=yes
# When zope mode is activated, consider the acquired-members option to ignore
# access to some undefined attributes.
zope=no
# List of members which are usually get through zope's acquisition mecanism and
# so shouldn't trigger E0201 when accessed (need zope=yes to be considered).
acquired-members=REQUEST,acl_users,aq_parent
# checks for :
# * doc strings
# * modules / classes / functions / methods / arguments / variables name
# * number of arguments, local variables, branchs, returns and statements in
# functions, methods
# * required module attributes
# * dangerous default values as arguments
# * redefinition of function / method / class
# * uses of the global statement
#
[BASIC]
# Required attributes for module, separated by a comma
required-attributes=
# Regular expression which should only match functions or classes name which do
# not require a docstring
no-docstring-rgx=__.*__
# Regular expression which should only match correct module names
module-rgx=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
# Regular expression which should only match correct module level names
const-rgx=(([A-Z_][A-Z1-9_]*)|(__.*__))$
# Regular expression which should only match correct class names
class-rgx=[A-Z_][a-zA-Z0-9]+$
# Regular expression which should only match correct function names
function-rgx=[a-z_][a-z0-9_]{2,30}$
# Regular expression which should only match correct method names
method-rgx=[a-z_][a-z0-9_]{2,30}$
# Regular expression which should only match correct instance attribute names
attr-rgx=[a-z_][a-z0-9_]{2,30}$
# Regular expression which should only match correct argument names
argument-rgx=[a-z_][a-z0-9_]{2,30}$
# Regular expression which should only match correct variable names
variable-rgx=[a-z_][a-z0-9_]{2,30}$
# Regular expression which should only match correct list comprehension /
# generator expression variable names
inlinevar-rgx=[A-Za-z_][A-Za-z0-9_]*$
# Good variable names which should always be accepted, separated by a comma
good-names=i,j,k,ex,Run,_
# Bad variable names which should always be refused, separated by a comma
bad-names=foo,bar,baz,toto,tutu,tata
# List of builtins function names that should not be used, separated by a comma
bad-functions=apply,input
# checks for sign of poor/misdesign:
# * number of methods, attributes, local variables...
# * size, complexity of functions, methods
#
[DESIGN]
# Maximum number of arguments for function / method
max-args=12
# Maximum number of locals for function / method body
max-locals=30
# Maximum number of return / yield for function / method body
max-returns=12
# Maximum number of branch for function / method body
max-branchs=30
# Maximum number of statements in function / method body
max-statements=60
# Maximum number of parents for a class (see R0901).
max-parents=7
# Maximum number of attributes for a class (see R0902).
max-attributes=20
# Minimum number of public methods for a class (see R0903).
min-public-methods=0
# Maximum number of public methods for a class (see R0904).
max-public-methods=20
# checks for
# * external modules dependencies
# * relative / wildcard imports
# * cyclic imports
# * uses of deprecated modules
#
[IMPORTS]
# Deprecated modules which should not be used, separated by a comma
deprecated-modules=regsub,string,TERMIOS,Bastion,rexec
# Create a graph of every (i.e. internal and external) dependencies in the
# given file (report R0402 must not be disabled)
import-graph=
# Create a graph of external dependencies in the given file (report R0402 must
# not be disabled)
ext-import-graph=
# Create a graph of internal dependencies in the given file (report R0402 must
# not be disabled)
int-import-graph=
# checks for :
# * methods without self as first argument
# * overridden methods signature
# * access only to existant members via self
# * attributes not defined in the __init__ method
# * supported interfaces implementation
# * unreachable code
#
[CLASSES]
# List of interface methods to ignore, separated by a comma. This is used for
# instance to not check methods defines in Zope's Interface base class.
ignore-iface-methods=isImplementedBy,deferred,extends,names,namesAndDescriptions,queryDescriptionFor,getBases,getDescriptionFor,getDoc,getName,getTaggedValue,getTaggedValueTags,isEqualOrExtendedBy,setTaggedValue,isImplementedByInstancesOf,adaptWith,is_implemented_by
# List of method names used to declare (i.e. assign) instance attributes.
defining-attr-methods=__init__,__new__,setUp
# checks for similarities and duplicated code. This computation may be
# memory / CPU intensive, so you should disable it if you experiments some
# problems.
#
[SIMILARITIES]
# Minimum lines number of a similarity.
min-similarity-lines=10
# Ignore comments when computing similarities.
ignore-comments=yes
# Ignore docstrings when computing similarities.
ignore-docstrings=yes
# checks for:
# * warning notes in the code like FIXME, XXX
# * PEP 263: source code with non ascii character but no encoding declaration
#
[MISCELLANEOUS]
# List of note tags to take in consideration, separated by a comma.
notes=FIXME,XXX,TODO
# checks for :
# * unauthorized constructions
# * strict indentation
# * line length
# * use of instead of !=
#
[FORMAT]
# Maximum number of characters on a single line.
max-line-length=90
# Maximum number of lines in a module
max-module-lines=1000
# String used as indentation unit. This is usually " " (4 spaces) or "\t" (1
# tab).
indent-string=' '
Related
I use OMNeT++ and I have this question about .ini files:
Why do we sometimes use * and sometimes we use ** to set parameters of NED modules?
According to the OMNeT++ Manual (Section 3.6.1)
* means A wildcard for any substring not containing a dot
** means A wildard for any sequence of characters including dots, so it can match multiple path elements
Example:
Lets assume you have the following modules:
aaa.bbb.value and aaa.ddd.value and ccc.bbb.value
**.value = 0 would address all modules, the path before is not important.
aaa.*.value = 0 would address the value element of aaa.bbb.value and aaa.ddd.value. ccc.bbb.value is not addressed because the wildcard is only for the middle substring of the path, as it contains no dots.
I am using Pylint to go through a bunch of .py files and do the following tests:
bad-indentation
mixed-indentation
unused-variable
I also want to have my pylintrc file as minimalist as possible. This is what I had in the begging:
[MASTER]
# Use multiple processes to speed up Pylint.
jobs=1
# Pickle collected data for later comparisons.
persistent=yes
# Allow loading of arbitrary C extensions. Extensions are imported into the
# active Python interpreter and may run arbitrary code.
unsafe-load-any-extension=no
[MESSAGES CONTROL]
# Disable all to choose the Tests one by one
disable=all
# Tests
enable=bad-indentation, # Used when an unexpected number of indentation’s tabulations or spaces has been found.
mixed-indentation, # Used when there are some mixed tabs and spaces in a module.
unused-variable # Used when a variable is defined but not used. (Use _var to ignore var).
[REPORTS]
# Set the output format. Available formats are text, parseable, colorized, json
# and msvs (visual studio).You can also give a reporter class, eg
# mypackage.mymodule.MyReporterClass.
output-format=text
# Tells whether to display a full report or only the messages
reports=no
# Activate the evaluation score.
score=no
[REFACTORING]
# Maximum number of nested blocks for function / method body
max-nested-blocks=5
[TYPECHECK]
# List of decorators that produce context managers, such as
# contextlib.contextmanager. Add to this list to register other decorators that
# produce valid context managers.
contextmanager-decorators=contextlib.contextmanager
# Tells whether missing members accessed in mixin class should be ignored. A
# mixin class is detected if its name ends with "mixin" (case insensitive).
ignore-mixin-members=yes
# This flag controls whether pylint should warn about no-member and similar
# checks whenever an opaque object is returned when inferring. The inference
# can return multiple potential results while evaluating a Python object, but
# some branches might not be evaluated, which results in partial inference. In
# that case, it might be useful to still emit no-member and other checks for
# the rest of the inferred objects.
ignore-on-opaque-inference=yes
# List of class names for which member attributes should not be checked (useful
# for classes with dynamically set attributes). This supports the use of
# qualified names.
ignored-classes=optparse.Values,thread._local,_thread._local
# Show a hint with possible names when a member name was not found. The aspect
# of finding the hint is based on edit distance.
missing-member-hint=yes
# The minimum edit distance a name should have in order to be considered a
# similar match for a missing member name.
missing-member-hint-distance=1
# The total number of similar names that should be taken in consideration when
# showing a hint for a missing member.
missing-member-max-choices=1
[MISCELLANEOUS]
# List of note tags to take in consideration, separated by a comma.
notes=FIXME,XXX,TODO
[SIMILARITIES]
# Ignore comments when computing similarities.
ignore-comments=yes
# Ignore docstrings when computing similarities.
ignore-docstrings=yes
# Ignore imports when computing similarities.
ignore-imports=no
# Minimum lines number of a similarity.
min-similarity-lines=4
[LOGGING]
# Logging modules to check that the string format arguments are in logging
# function parameter format
logging-modules=logging
[BASIC]
# Naming hint for argument names
argument-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Regular expression matching correct argument names
argument-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Naming hint for attribute names
attr-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Regular expression matching correct attribute names
attr-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Bad variable names which should always be refused, separated by a comma
bad-names=foo,bar,baz,toto,tutu,tata
# Naming hint for class attribute names
class-attribute-name-hint=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
# Regular expression matching correct class attribute names
class-attribute-rgx=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
# Naming hint for class names
class-name-hint=[A-Z_][a-zA-Z0-9]+$
# Regular expression matching correct class names
class-rgx=[A-Z_][a-zA-Z0-9]+$
# Naming hint for constant names
const-name-hint=(([A-Z_][A-Z0-9_]*)|(__.*__))$
# Regular expression matching correct constant names
const-rgx=(([A-Z_][A-Z0-9_]*)|(__.*__))$
# Minimum line length for functions/classes that require docstrings, shorter
# ones are exempt.
docstring-min-length=-1
# Naming hint for function names
function-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Regular expression matching correct function names
function-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Good variable names which should always be accepted, separated by a comma
good-names=i,j,k,ex,Run,_
# Include a hint for the correct naming format with invalid-name
include-naming-hint=no
# Naming hint for inline iteration names
inlinevar-name-hint=[A-Za-z_][A-Za-z0-9_]*$
# Regular expression matching correct inline iteration names
inlinevar-rgx=[A-Za-z_][A-Za-z0-9_]*$
# Naming hint for method names
method-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Regular expression matching correct method names
method-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Naming hint for module names
module-name-hint=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
# Regular expression matching correct module names
module-rgx=(([a-z_][a-z0-9_]*)|([A-Z][a-zA-Z0-9]+))$
# Regular expression which should only match function or class names that do
# not require a docstring.
no-docstring-rgx=^_
# List of decorators that produce properties, such as abc.abstractproperty. Add
# to this list to register other decorators that produce valid properties.
property-classes=abc.abstractproperty
# Naming hint for variable names
variable-name-hint=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
# Regular expression matching correct variable names
variable-rgx=(([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$
[VARIABLES]
# List of additional names supposed to be defined in builtins. Remember that
# you should avoid to define new builtins when possible.
#additional-builtins=
# Tells whether unused global variables should be treated as a violation.
allow-global-unused-variables=yes
# List of strings which can identify a callback function by name. A callback
# name must start or end with one of those strings.
callbacks=cb_,_cb
# A regular expression matching the name of dummy variables (i.e. expectedly
# not used).
dummy-variables-rgx=_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_
# Argument names that match this expression will be ignored. Default to name
# with leading underscore
ignored-argument-names=_.*|^ignored_|^unused_
# Tells whether we should check for unused import in __init__ files.
init-import=no
# List of qualified module names which can have objects that can redefine
# builtins.
redefining-builtins-modules=six.moves,future.builtins
[SPELLING]
# Tells whether to store unknown words to indicated private dictionary in
# --spelling-private-dict-file option instead of raising a message.
spelling-store-unknown-words=no
[FORMAT]
# Regexp for a line that is allowed to be longer than the limit.
ignore-long-lines=^\s*(# )?<?https?://\S+>?$
# Number of spaces of indent required inside a hanging or continued line.
indent-after-paren=4
# String used as indentation unit. This is usually " " (4 spaces) or "\t" (1
# tab).
indent-string=' '
# Maximum number of characters on a single line.
max-line-length=125
# Maximum number of lines in a module
max-module-lines=1000
# List of optional constructs for which whitespace checking is disabled. `dict-
# separator` is used to allow tabulation in dicts, etc.: {1 : 1,\n222: 2}.
# `trailing-comma` allows a space between comma and closing bracket: (a, ).
# `empty-line` allows space-only lines.
no-space-check=trailing-comma,dict-separator
# Allow the body of a class to be on the same line as the declaration if body
# contains single statement.
single-line-class-stmt=no
# Allow the body of an if to be on the same line as the test if there is no
# else.
single-line-if-stmt=no
[CLASSES]
# List of method names used to declare (i.e. assign) instance attributes.
defining-attr-methods=__init__,__new__,setUp
# List of member names, which should be excluded from the protected access
# warning.
exclude-protected=_asdict,_fields,_replace,_source,_make
# List of valid names for the first argument in a class method.
valid-classmethod-first-arg=cls
# List of valid names for the first argument in a metaclass class method.
valid-metaclass-classmethod-first-arg=mcs
[IMPORTS]
# Allow wildcard imports from modules that define __all__.
allow-wildcard-with-all=no
# Analyse import fallback blocks. This can be used to support both Python 2 and
# 3 compatible code, which means that the block might have code that exists
# only in one or another interpreter, leading to false positives when analysed.
analyse-fallback-blocks=no
# Deprecated modules which should not be used, separated by a comma
deprecated-modules=regsub,TERMIOS,Bastion,rexec
# Force import order to recognize a module as part of a third party library.
known-third-party=enchant
[DESIGN]
# Maximum number of arguments for function / method
max-args=5
# Maximum number of attributes for a class (see R0902).
max-attributes=7
# Maximum number of boolean expressions in a if statement
max-bool-expr=5
# Maximum number of branch for function / method body
max-branches=12
# Maximum number of locals for function / method body
max-locals=15
# Maximum number of parents for a class (see R0901).
max-parents=7
# Maximum number of public methods for a class (see R0904).
max-public-methods=20
# Maximum number of return / yield for function / method body
max-returns=6
# Maximum number of statements in function / method body
max-statements=50
# Minimum number of public methods for a class (see R0903).
min-public-methods=2
[EXCEPTIONS]
# Exceptions that will emit a warning when being caught.
overgeneral-exceptions=Exception
Can I just simplify it to this:
[MASTER]
# Use multiple processes to speed up Pylint.
jobs=1
[MESSAGES CONTROL]
# Disable all to choose the Tests one by one
disable=all
# Tests
enable=bad-indentation, # Used when an unexpected number of indentation’s tabulations or spaces has been found.
mixed-indentation, # Used when there are some mixed tabs and spaces in a module.
unnecessary-semicolon, # Used when a statement is ended by a semi-colon (”;”), which isn’t necessary.
unused-variable # Used when a variable is defined but not used. (Use _var to ignore var).
[REPORTS]
# Tells whether to display a full report or only the messages
reports=no
# Activate the evaluation score.
score=no
[FORMAT]
# Regexp for a line that is allowed to be longer than the limit.
ignore-long-lines=^\s*(# )?<?https?://\S+>?$
# Number of spaces of indent required inside a hanging or continued line.
indent-after-paren=4
# String used as indentation unit. This is usually " " (4 spaces) or "\t" (1
# tab).
indent-string=' '
# Maximum number of lines in a module
max-module-lines=1000
[EXCEPTIONS]
# Exceptions that will emit a warning when being caught.
overgeneral-exceptions=Exception
I believe that if I'm only doing those tests many of the other lines were completely useless. What happens if I remove one of the lines? Does it get its default values?
For example if I set reports=no I don't need to have the line output-format=text, right? And if I remove jobs=1 line will it still be the default?
Yes, if you don't define any value in the pylint configuration, it is going to use its default known value.
How to disable "No space allowed around keyword argument assignment" in Pylint?
I found why it checks for the spaces (PEP 8, why no spaces around '=' in keyword argument or a default parameter value?), but I don't agree because this means I need to spend hours of solving only this message.
I looked for the message so I can disable it in the rcfile here: http://pylint-messages.wikidot.com/all-codes
But the message does not appear in the pylint documentation?!
Disabling in Pylint
This can be disabled in Pylint with bad-whitespace:
$ cat a.py
myfunca(myargb = 3)
$ pylint a.py --reports=n
No config file found, using default configuration
************* Module a
C: 1, 0: No space allowed around keyword argument assignment
myfunca(myargb = 3)
^ (bad-whitespace)
C: 1, 0: Missing module docstring (missing-docstring)
E: 1, 0: Undefined variable 'myfunca' (undefined-variable)
$ pylint a.py --disable bad-whitespace --reports=n
No config file found, using default configuration
************* Module a
C: 1, 0: Missing module docstring (missing-docstring)
E: 1, 0: Undefined variable 'myfunca' (undefined-variable)
Disabling in PEP8 Checker
For completeness, you can disable the same for pep8's checker with E251:
$ pep8 a.py
a.py:1:15: E251 unexpected spaces around keyword / parameter equals
a.py:1:17: E251 unexpected spaces around keyword / parameter equals
$ pep8 a.py --ignore=E251
Update - Info on suppressing just that message
AFAIK you can only disable messages down to the granularity of IDs in pylint, as all the whitespace has the same id bad-whitespace aka C0326 you can therefore either ignore all or none.
This is the code that checks if a message is disabled, as you see it only receives the id to check against:
def is_message_enabled(self, msg_descr, line=None, confidence=None):
"""return true if the message associated to the given message id is
enabled
msgid may be either a numeric or symbolic message id.
"""
When the message is added to the lint results, you can see that bad-whitespace is all that is passed in. The around and keyword argument assignment are simply arguments to the message.
warnings = []
if not any(good_space) and policies[0] == policies[1]:
warnings.append((policies[0], 'around'))
else:
for ok, policy, position in zip(good_space, policies, ('before', 'after')):
if not ok:
warnings.append((policy, position))
for policy, position in warnings:
construct = _name_construct(token)
count, state = _policy_string(policy)
self.add_message('bad-whitespace', line=token[2][0],
args=(count, state, position, construct,
_underline_token(token)))
The arguments to the message are displayed using the formatting string:
'C0326': ('%s space %s %s %s\n%s',
'bad-whitespace',
('Used when a wrong number of spaces is used around an operator, '
'bracket or block opener.'),
All that should help if you want to customize pylint to do what you want, and if so, a pull-request back to them would hopefully be well received.
One way in which we can ignore a specific pylint check is to include the following line at the top of your python code -
# pylint: disable=C0326
# pylint: disable=C0303
... your code goes here
pylint then ignores the mentioned warnings as well as ignores these checks while calculating the pylint score.
For the above code, it will ignore both Trailing whitespaces (C0303) and Space before and after brackets, operators, comma (C0326)
When you type something, you often use bash autocompletion: you start writing a command, for example, and you type TAB to get the rest of the word.
As you have probably noticed, when multiple choices match your command, bash displays them like this :
foobar#myserv:~$ admin-
admin-addrsync admin-adduser admin-delrsync admin-deluser admin-listsvn
admin-addsvn admin-chmod admin-delsvn admin-listrsync
I'm looking for a solution to display each possible solution on a new line, similar to the last column on a ls -l. Ever better, it would be perfect if I could apply a rule like this: "if you find less than 10 suggestions, display them one by line, if more => actual display".
bash prior to version 4.2 doesn't allow any control over the output format of completions, unfortunately.
Bash 4.2+ allows switching to 1-suggestion-per-line output globally, as explained in Grisha Levit's helpful answer, which also links to a clever workaround to achieve a per-completion-function solution.
The following is a tricky workaround for a custom completion.
Solving this problem generically, for all defined completions, would be much harder (if there were a way to invoke readline functions directly, it might be easier, but I haven't found a way to do that).
To test the proof of concept below:
Save to a file and source it (. file) in your interactive shell - this will:
define a command named foo (a shell function)
whose arguments complete based on matching filenames in the current directory.
(When foo is actually invoked, it simply prints its argument in diagnostic form.)
Invoke as:
foo [fileNamePrefix], then press tab:
If between 2 and 9 files in the current directory match, you'll see the desired line-by-line display.
Otherwise (1 match or 10 or more matches), normal completion will occur.
Limitations:
Completion only works properly when applied to the LAST argument on the command line being edited.
When a completion is actually inserted in the command line (once the match is unambiguous), NO space is appended to it (this behavior is required for the workaround).
Redrawing the prompt the first time after printing custom-formatted output may not work properly: Redrawing the command line including the prompt must be simulated and since there is no direct way to obtain an expanded version of the prompt-definition string stored in $PS1, a workaround (inspired by https://stackoverflow.com/a/24006864/45375) is used, which should work in typical cases, but is not foolproof.
Approach:
Defines and assigns a custom completion shell function to the command of interest.
The custom function determines the matches and, if their count is in the desired range, bypasses the normal completion mechanism and creates custom-formatted output.
The custom-formatted output (each match on its own line) is sent directly to the terminal >/dev/tty, and then the prompt and command line are manually "redrawn" to mimic standard completion behavior.
See the comments in the source code for implementation details.
# Define the command (function) for which to establish custom command completion.
# The command simply prints out all its arguments in diagnostic form.
foo() { local a i=0; for a; do echo "\$$((i+=1))=[$a]"; done; }
# Define the completion function that will generate the set of completions
# when <tab> is pressed.
# CAVEAT:
# Only works properly if <tab> is pressed at the END of the command line,
# i.e., if completion is applied to the LAST argument.
_complete_foo() {
local currToken="${COMP_WORDS[COMP_CWORD]}" matches matchCount
# Collect matches, providing the current command-line token as input.
IFS=$'\n' read -d '' -ra matches <<<"$(compgen -A file "$currToken")"
# Count matches.
matchCount=${#matches[#]}
# Output in custom format, depending on the number of matches.
if (( matchCount > 1 && matchCount < 10 )); then
# Output matches in CUSTOM format:
# print the matches line by line, directly to the terminal.
printf '\n%s' "${matches[#]}" >/dev/tty
# !! We actually *must* pass out the current token as the result,
# !! as it will otherwise be *removed* from the redrawn line,
# !! even though $COMP_LINE *includes* that token.
# !! Also, by passing out a nonempty result, we avoid the bell
# !! signal that normally indicates a failed completion.
# !! However, by passing out a single result, a *space* will
# !! be appended to the last token - unless the compspec
# !! (mapping established via `complete`) was defined with
# !! `-o nospace`.
COMPREPLY=( "$currToken" )
# Finally, simulate redrawing the command line.
# Obtain an *expanded version* of `$PS1` using a trick
# inspired by https://stackoverflow.com/a/24006864/45375.
# !! This is NOT foolproof, but hopefully works in most cases.
expandedPrompt=$(PS1="$PS1" debian_chroot="$debian_chroot" "$BASH" --norc -i </dev/null 2>&1 | sed -n '${s/^\(.*\)exit$/\1/p;}')
printf '\n%s%s' "$expandedPrompt" "$COMP_LINE" >/dev/tty
else # Just 1 match or 10 or more matches?
# Perform NORMAL completion: let bash handle it by
# reporting matches via array variable `$COMPREPLY`.
COMPREPLY=( "${matches[#]}" )
fi
}
# Map the completion function (`_complete_foo`) to the command (`foo`).
# `-o nospace` ensures that no space is appended after a completion,
# which is needed for our workaround.
complete -o nospace -F _complete_foo -- foo
bash 4.2+ (and, more generally, applications using readline 6.2+) support this with the use of the completion-display-width variable.
The number of screen columns used to display possible matches when performing completion. The value is ignored if it is less than 0 or greater than the terminal screen width. A value of 0 will cause matches to be displayed one per line. The default value is -1.
Run the following to set the behavior for all completions1 for your current session:
bind 'set completion-display-width 0'
Or modify your ~/.inputrc2 file to have:
set completion-display-width 0
to change the behavior for all new shells.
1 See here for a method for controlling this behavior for individual custom completion functions.
2 The search path for the readline init file is $INPUTRC, ~/.inputrc, /etc/inputrc so modify the file appropriate for you.
I've modified a regex that I found here so that it would accept various UK and second-level TLDs.
/\b((?:^https?:\/\/|^[a-z0-9.\-]+[.][a-z]{2,4})(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!#()\[\]{};:'".,<>?]))/i
However as you can see in my test data here, the regex matches URLs such as www.zapple.#com and https://m!crosoft.com which are not valid.
For some reason # symbols are excluded before the .com but after the . they are not.
Exclamation marks are not excluded at all which is confusing since, as far as I can see, only letters, numbers and dashes are allowed before the period.
The # is matched by
[^\s()<>]+
And the ! mark by
(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+
I don't know but that doesn't look like a good regex to match url's
Try the following which matches a url according to RFC 3986
Both absolute and relative url'sare supported.
Set case insensitivity to true
^
(# Scheme
[a-z][a-z0-9+\-.]*:
(# Authority & path
//
([a-z0-9\-._~%!$&'()*+,;=]+#)? # User
([a-z0-9\-._~%]+ # Named host
|\[[a-f0-9:.]+\] # IPv6 host
|\[v[a-f0-9][a-z0-9\-._~%!$&'()*+,;=:]+\]) # IPvFuture host
(:[0-9]+)? # Port
(/[a-z0-9\-._~%!$&'()*+,;=:#]+)*/? # Path
|# Path without authority
(/?[a-z0-9\-._~%!$&'()*+,;=:#]+(/[a-z0-9\-._~%!$&'()*+,;=:#]+)*/?)?
)
|# Relative URL (no scheme or authority)
([a-z0-9\-._~%!$&'()*+,;=#]+(/[a-z0-9\-._~%!$&'()*+,;=:#]+)*/? # Relative path
|(/[a-z0-9\-._~%!$&'()*+,;=:#]+)+/?) # Absolute path
)
# Query
(\?[a-z0-9\-._~%!$&'()*+,;=:#/?]*)?
# Fragment
(\#[a-z0-9\-._~%!$&'()*+,;=:#/?]*)?
$
Update 1
This does not match m!crosoft.com and #pple.com It's probably due to someting with Rublar.