I need to find only files in directory which have a extension using ls (can't use find).
I tried ls *.*, but if dir doesn't contain any file with extension it returns "No such file or directory".
I dont want that error and want ls to return to cmd prompt if there are files with extension.
I have trying to use grep with ls to achieve the same.
ls|grep "*.*" - doesn't work
but ls | grep "\." works.
I have no idea why grep *.* doesn't work. Any help is appreciated!
Thanks!
I think the correct solution is this:
( shopt -s nullglob ; echo *.* )
It's a bit verbose, but it will always work no matter what kind of funky filenames you have. (The problem with piping ls to grep is that typical systems allow really bizarre characters in filenames, including, for example, newlines.)
The shopt -s nullglob part enables ("sets") the nullglob shell optoption, which tells Bash that if no files have names matching *.*, then the *.* should be removed (i.e., should expand into nothing) rather than being left alone.
The parentheses (...) are to set up a subshell, so the nullglob option is only enabled for this small part of the script.
It's important to understand the difference between a shell pattern and a regular expression. Shell patterns are a bit simpler, but less flexible. grep matches using a regular expression. A shell pattern like
*.*
would be done with a regular expression as
.*\..*
but the regular expressions in grep are not anchored, which means it searches for a match anywhere on the line, making the two .* parts unnecessary.
Try
ls -1 | grep "\."
list only files with extensión and nothing (empty list) if there is no file: like you need.
With Linux grep, you can add -v to get a list files with no extension.
Related
I'm attempting to find all .PHP files that are in certain depth of a directory (at least 4 levels down, but not more than 5 levels in).
I'm logged into my Centos server with root authority via shell.
The string I want to search for is:
$slides='';
What I have in front of me.. I would expect it to work. I tried to escape the $ with a \ (I thought perhaps it works like regex, needing special chars excluded). I tried without the ='' portion, or tried adding \'\' to that part.. or remove the ='' altogether to simplify. nothing.
find . -maxdepth 5 -mindepth 4 -type f -name ‘*.php’ -print | xargs grep "\$slides=’’" *
I'm already running it under the directory under which I want to recursively search.
Also - I have the filter to look for *.php only but I still get a bunch of directory names in the return with a warning that says grep: [dir_name]: Is a directory
Clearly I am missing something here as far as syntax of grep command goes, or how the filter works here. I use grep more in PHP so this is quite a transition for me!
So you were almost right. The problem looks to have been the grep part of the command
grep "\$slides=''" *
Namely the * was the issue. From the bash manual
After word splitting, unless the -f option has been set (see The Set
Builtin), Bash scans each word for the characters ‘*’, ‘?’, and ‘[’.
If one of these characters appears, and is not quoted, then the word
is regarded as a pattern, and replaced with an alphabetically sorted
list of filenames matching the pattern
When you piped the found files with find into xargs and attempted to grep them with *, grep would have interpreted this as you wanting to find the string $slides='' in a list of filenames/directories returned by the glob *, and you cannot grep directories without supplying the -r flag to grep, so it returned an error.
Instead, what you wanted to do is pipe the found files with find into xargs so it can add the list of filenames to the grep command, as that's what xargs does. From the xargs manual
xargs reads items from the standard input, delimited by blanks (which
can be protected with double or single quotes or a backslash) or
newlines, and executes the command (default is /bin/echo) one or more
times with any initial- arguments followed by items read from
standard input. Blank lines on the standard input are ignored.
Making the correct command
find . -maxdepth 5 -mindepth 4 -type f -name '*.php' -print0 | xargs -0 grep "\$slides=''"
Using the -print0 flag in find, and the -0 flag in xargs, to use NUL as the delimiter, in case any filenames contained newlines.
If you want to use shell_exec from your PHP code, it is a program execution function which allows you to run a command like 'ls -al' in the operating system shell and get the result returned into a variable. Querystrings are not commands you can use in this way.
Do you mean running PHP from the command line so that it runs from the shell, not from the web server:
php -r 'echo "hello world\n";'
If you run PHP 4.3 and above, you can use the PHP Command Line Interface (CLI) which can also execute scripts stored in files. Have a look at the syntax and examples at: http://php.net/features.commandline
I am trying to get the most recent .CSV or .csv file name among other comma separated value files where the extension name is case insensitive.
I am achieving this with the following command, provided by someone else without any explanation:
ls -t ~(i:*.CSV) | head -1
or
ls -t -- ~(i:*.CSV) | head -1
I have two questions:
What is the use of ~ and -- in this case? Does -- helps here?
How can I get a blank response when there is no .csv or .CSV file in
the folder? At the moment I get:
/bin/ls: cannot access ~(i:*.CSV): No such file or directory
I know I can test the exit code of the last command, but I was wondering maybe there is a --silent option or something.
Many thanks for your time.
PS: I made my research online quite thorough and I was unable to find an answer.
The ~ is just a literal character; the intent would appear to be to match filenames starting with ~ and ending with .csv, with i: being a flag to make the match case-insensitive. However, I don't know of any shell that supports that particular syntax. The closest thing I am aware of would be zsh's globbing flags:
setopt extended_glob # Allow globbing flags
ls ~(#i)*.csv
Here, (#i) indicates that anything after it should be matched without regard to case.
Update: as #baptistemm points out, ~(i:...) is syntax defined by ksh.
The -- is a conventional argument, supported by many commands, to mean that any arguments that follow are not options, but should be treated literally. For example, ls -l would mean ls should use the -l option to modify its output, while ls -- -l means ls should try to list a file named -l.
~(i:*.CSV) is to tell to shell (this is only supported apparently in ksh93) the enclosed text after : must be treated as insensitive, so in this example that could all these possibilites.
*.csv or
*.Csv or
*.cSv or
*.csV or
*.CSv or
*.CSV
Note this could have been written ls -t *.[CcSsVv] in bash.
To silent errors I suggest you to look for in this site for "standard error /dev/null" that will help.
I tried running commands like what you have in both bash and zsh and neither worked, so I can't help you out with that, but if you want to discard the error, you can add 2>/dev/null to the end of the ls command, so your command would look like the following:
ls -t ~(i:*.CSV) 2>/dev/null | head -1
This will redirect anything written to STDERR to /dev/null (i.e. throw it out), which, in your case, would be /bin/ls: cannot access ~(i:*.CSV): No such file or directory.
I want to copy all files from /usr/lib which ends with .X.0.0 where X is an even number. Is there a better way than the following one to select all the files?
ls /usr/lib | grep "[02468].0.0$"
My problem with this solutions is that in case there are files with names like "xy.800.0.0" I need to use the bracket three times etc.
Just use a glob expansion to match the files:
cp /usr/lib/*.*[02468].0.0 /path/to/destination
The shell expands this pattern to the list of files before passing them as arguments to cp.
Since you tagged Bash, you can make the match more strict by using an extended glob:
shopt -s extglob failglob
cp /usr/lib/*.*([0-9])[02468].0.0 /path/to/destination
This matches 0 or more other digits followed by an even digit, and doesn't run the command at all if no files match.
You could use extended grep regular expressions to only match even numbers:
ls -1q /usr/lib | grep -E "\.[0-9]*[02468].0.0$"
However, as Tom suggested, there are better options than parsing the output of ls. It's generally safer and faster to use glob expansion, and more maintainable to just put everything in a python script.
I want to search a filename which may contain kavi or kabhi.
I wrote command in the terminal:
ls -l *ka[vbh]i*
Between ka and i there may be v or bh .
The code I wrote isn't correct. What would be the correct command?
A nice way to do this is to use extended globs. With them, you can perform regular expressions on Bash.
To start you have to enable the extglob feature, since it is disabled by default:
shopt -s extglob
Then, write a regex with the required condition: stuff + ka + either v or bh + i + stuff. All together:
ls -l *ka#(v|bh)i*
The syntax is a bit different from the normal regular expressions, so you need to read in Extended Globs that...
#(list): Matches one of the given patterns.
Test
$ ls
a.php AABB AAkabhiBB AAkabiBB AAkaviBB s.sh
$ ls *ka#(v|bh)i*
AAkabhiBB AAkaviBB
a slightly longer cmd line could be using find, grep and xargs. it has the advantage of being easily extended to different search terms (by either extending the grep statement or by using additional options of find), a bit more readability (imho) and flexibility in being able to execute specific commands on the files which are found
find . | grep -e "kabhi" -e "kavi" | xargs ls -l
You can get what you want by using curly braces in bash:
ls -l *ka{v,bh}i*
Note: this is not a regular expression question so much as a "shell globbing" question. Shell "glob patterns" are different from regular expressions, though they are similar in many ways.
Can we search a term (eg. "onblur") recursively in some folders only in specific files (html files)?
grep -Rin "onblur" *.html
This returns nothing. But,
grep -Rin "onblur" .
returns "onblur" search result from all available files, like in text(".txt"), .mako, .jinja etc.
Consider checking this answer and that one.
Also this might help you: grep certain file types recursively | commandlinefu.com.
The command is:
grep -r --include="*.[ch]" pattern .
And in your case it is:
grep -r --include="*.html" "onblur" .
grep -r --include "*.html" onblur .
Got it from :
How do I grep recursively?
You might also like ag 'the silver searcher' -
ag --html onblur
it searches by regexp and is recursive in the current directory by default, and has predefined sets of extensions to search - in this case --html maps to .htm, .html, .shtml, .xhtml. Also ignores binary files, prints filenames, line numbers, and colorizes output by default.
Some options -
-Q --literal
Do not parse PATTERN as a regular expression. Try to match it literally.
-S --smart-case
Match case-sensitively if there are any uppercase letters in PATTERN,
case-insensitively otherwise. Enabled by default.
-t --all-text
Search all text files. This doesn't include hidden files.
--hidden
Search hidden files. This option obeys ignored files.
For the list of supported filetypes run ag --list-file-types.
The only thing it seems to lack is being able to specify a filetype with an extension, in which case you need to fall back on grep with --include.
To be able to grep only from .py files by typing grepy mystring I added the following line to my bashrc:
alias grepy='grep -r --include="*.py"'
Also note that grep accepts The following:
grep mystring *.html
for .html search in current folder
grep mystring */*.html
for recursive search (excluding any file in current dir!).
grep mystring .*/*/*.html
for recursive search (all files in current dir and all files in subdirs)
Have a look at this answer instead, to a similar question: grep, but only certain file extensions
This worked for me. In your case just type the following:
grep -inr "onblur" --include \*.html ./
consider that
grep: command
-r: recursively
-i: ignore-case
-n: each output line is preceded by its relative line number in the file
--include \*.html: escape with \ just in case you have a directory with asterisks in the filenames
./: start at current directory.