I’m using a GNU/Linux distribution where the utility rename comes from util-linux and I want to make full use of regular (Perl or POSIX) expressions with it.
There are two versions of rename :
The “Perl” version, with syntax rename 's/^fgh/jkl/' fgh*
The util-linux version, with syntax rename fgh jkl fgh*
If the use of regexes seems pretty obvious with the first one, to which I have no easy access. However, I’m confused about the second one: I could not find any relevant documentation or examples on the possible use, and in that case the format, of the regular expressions to use.
Let’s take, to make a simple example, a directory containing:
foo_a1.ext
foo_a32.ext
foo_c18.ext
foo_h12.ext
I want to use a syntax like one of these two lines:
rename "foo_[a-z]([0-9]{1,2}).ext" "foo_\1.ext" *
rename "foo_[:alpha:]([:digit:]{1,2}).ext" "foo_\1.ext" *
for which the expected output would be:
foo_1.ext
foo_32.ext
foo_18.ext
foo_12.ext
Of course this does not work! Either I’m missing something obvious, or there is
no implemented way to use actual regular expressions with this tool.
(Please note that I am aware of the other possibilities for renaming files with regular expressions in a shell interpreter; this question aims at a specific version of the rename tool.)
Here is the manual page: http://linux.die.net/man/1/rename. It is pretty straightforward:
rename from to file...
rename will rename the specified files by replacing the first
occurrence of from in their name by to.
I believe there are no regexes, it is just plain substring match.
The following command gives the expected result with your input file but using the perl version:
rename 's/foo_\D+(\d+)/foo_$1/' *.ext
You can test the command using -n option to rename
Related
Currently I am working on a fairly large project. In order to increase the quality of our code, we decided to enforce the treatement of return values (Error Codes) for every function. GCC supports a warning concerning the return value of a function, however the function definition has to be preceeded by the following flag.
static __attribute__((warn_unused_result)) ErrorCode test() { /* code goes here */ }
I want to implement a bashscript that parses the entire source code and issues a warning in case the
__attribute__((warn_unused_result))
is missing.
Note that all functions that require this kind of modification return a type called ErrorCode.
Do you think this is possible via a bash script ?
Maybe you can use sed with regular expressions. The following worked for me on a couple of test files I tried:
sed -r "s/ErrorCode\s+\w+\s*(.*)\s*\{/__attribute__((warn_unused_result)) \0/g" test.cpp
If you're not familiar with regex, the pattern basically translates into:
ErrorCode, some whitespace, some alphanumerics (function name), maybe some whitespace, open parenthesis, anything (arguments), close parenthesis, maybe some whitespace, open curly brace.
If this pattern is found, it is prefixed by __attribute__((warn_unused_result)). Note that this only works if you are putting the open curly brace always in the same line as the arguments and you don't have line breaks in your function declarations.
An easy way I could imagine is via ctags. You create a tag file over all your source code, and then parse the tags file. However, I'm not quite sure about the format of the tags file. The variant I'm using here (Exuberant Ctags 5.8) seems to put an "f" in the fourth column, if the tag represents a function. So in this case I would use awk to filter all tags that represent functions, and then grep to throw away all lines without __attribute__((warn_unused_result)).
So, in a nutshell, first you do
$ ctags **/*.c
This creates a file called "tags" in the current directory. The command might also be ctags-exuberant, depending on your variant. The **/*.c is a glob pattern that might work in your shell - if it doesn't, you have to supply your source files in another way (look at the ctagsoptions).
Then you filter the funktions:
$ cat tags | awk -F '\t' '$4 == "f" {print $0}' | grep -v "__attribute__((warn_unused_result))"
No, it is not possible in the general case. The C++ grammar is the most complex of all the languages I know of, and C++ is not parsable via regular expressions in the general case. You might succeed if you limit yourself to a very narrow set of uses, but I am not sure how feasible it is in your case.
I also do not think the excersise is worth the effort, since sometimes ignoring the result of the function is an OK thing.
I have a bunch of PHP coded websites that have been recently moved to a PHP 5.4 server and they're throwing deprecation warnings and errors.
Is there a way to mass find & replace function names with the proper ones? For example, I would like to be able to replace all instances of session_unregister('someVar') with unset($_SESSION['someVar'])...
Should i use regex or is there an other way?
For this particular example you could use sed like this:
echo "session_unregister('someVar')" | sed 's/session_unregister(/unset\($_SESSION[/;s/)/])/'
A bit more flexible would be to use the C preprocessor. Assume your php source file name is my.php. Add extension .h so it becomes my.php.h. At the beginning of the file, insert:
#define session_unregister(X) unset($_SESSION[X])
Assume the file contains lines like in your example: session_unregister('someVar')
Run the preprocessor like this:
cc -E my.php.h
Now you should instead see unset($_SESSION['someVar'])
(plus some extra garbage you don't want).
Note that this just answers your particular question, but I wouldn't recommend it without more detailed testing.
I am writing a long document and I am frequently formatting some terms to italics. After some time I realized that maybe that is now what I want so I would like to remove all the latex commands that format text to italics.
Example:
\textit{Vim} is undoubtedly one of the best editors ever made. \textit{LaTeX} is an extremely powerful, intelligent typesetter. \textbd{Vim-LaTeX} aims at bringing together the best of both these worlds
How can I run a substitution command that recognizes all the instances of \textit{whatever} and changes them to just whatever without affecting different commands such as \textbd{Vim-LaTeX} in this example?
EDIT: As technically the answer that helps is the one from Igor I will mark that one as the correct one. Nevertheless, Konrad's answer should be taken into account as it shows the proper Latex strategy to follow.
You shouldn’t use formatting commands at all in your text.
LaTeX is built around the idea of semantic markup. So instead of saying “this text should be italic” you should mark up the text using its function. For instance:
\product{Vim} is undoubtedly one of the best editors ever made. \product{LaTeX}
is an extremely powerful, intelligent typesetter. \product{Vim-LaTeX} aims at
bringing together the best of both these worlds
… and then, in your preamble, a package, or a document class, you (re-)define a macro \product to set the formatting you want. That way, you can adapt the macro whenever you deem necessary without having to change the code.
Or, if you want to remove the formatting completely, just make the macro display its bare argument:
\newcommand*\product[1]{#1}
Use this substitution command:
% s/\\textit{\([^}]*\)}/\1/
If textit can span muptiple lines:
%! perl -e 'local $/; $_=<>; s/\\textit{([^}]*)}/$1/g; print;'
And you can do this without perl also:
%s/\\textit{\(\_.\{-}\)}/\1/g
Here:
\_. -- any symbol including a newline character
\{-} -- make * non-greedy.
I'm working on refactoring a bunch of PHP code for an instructor. The first thing I've decided to do is to update all the SQL files to be written in Drupal SQL coding conventions, i.e., to have all-uppercase keywords. I've written a few regular expressions:
:%s/create table/CREATE TABLE/gi
:%s/create database/CREATE DATABASE/gi
:%s/primary key/PRIMARY KEY/gi
:%s/auto_increment/AUTO_INCREMENT/gi
:%s/not null/NOT NULL/gi
Okay, that's a start. Now I just open every SQL file in Vim, run all five regular expressions, and save. This feels like five times the work it should be. Can they be compounded in to one obnoxiously long but easily copy-pastable regex?
why do you have to do it in vim? how about sed/awk?
e.g. with sed
sed -e 's/create table/\U&/g' -e's/not null/\U&/g' -e 's/.../\U&/' *.sql
btw, in vi you may do
:%s/create table/\U&/g
to change case, well save some typing.
update
if you really want a long command to execute in vi, maybe you could try:
:%s/create table\|create database\|foo\|bar\|blah/\U&/g
Open the file containing that substitution commands.
Copy its contents (to the unnamed register, by default):
:%y
If there is only one file where the substitutions should be
performed, open it as usual and run the contents of that register
as a Normal mode command:
:#"
If there are several files to edit automatically, open those
files as arguments:
:args *.sql
Execute the yanked substitutions for each file in the argument list:
:argdo #"|up
(The :update command running after the substitutions, writes
the buffer to file if it has been changed.)
While sed can handle what you want (hovewer it can be interactive as you requestred by flag 'i'), vim still much powerfull. Once I needed to change last argument in some function call in 1M SLOC code base. The arguments could be in one line or in several lines. In vim I achieved it pretty easy.
You can open all php files in vim at once:
vim *.php
After that run in ex mode:
:bufdo! %s/create table/CREATE TABLE/gi
Repeat the rest of commands. At the end save all the files and exit vim:
:xall
Is there any way to write a RegEx which can be used to find files with different Extensions.
This works in Bash:
find . -regex '.*\\.\\(pdf\|chm\|doc\\)'
Assuming you have a list of files and you are looking for .pdf, .chm and .doc, you can check it with:
\.pdf$|\.chm$|\.doc$
Regex above should work if you will check it against single filenames.
I'm sure there is, but the question you should be asking is "What's the best way to find files which have specific extensions?".
Regular expressions are not the best answer to every question.
I would suggest just getting a list of all files and passing them into a function like IsThisFileOneIWant(fileName,extensionList). That's far easier than trying to shoehorn the use of regular expressions into your problem.
Something like this should do it:
function IsThisFileOneIWant(fileName,extensionList):
for each extension in extensionList:
if fileName.endsWith (extension):
return true
return false
Done in pseudo-code since it should be simple enough to turn into any other language.
If you must have a regex, it's going to look something like (based on the values in your question):
"ASPX$|ASCX$|\.js$|\.rpt$|\.xml$"
but it depends entirely on the RE engine that you want to use. For example, here's the output from an egrep command in my work directory:
pax#paxbox1:~/work$ ls -1 | egrep '\.sh$|\.c$'
backup0.sh
backup1.sh
eclipse.sh
monbt.sh
qq.c
qq.sh
xx yy.sh