Get the Files Inside a Directory

How can I get the list of files in a directory using C or C++?

UPDATE 2017:

In C++17 there is now an official way to list files of your file system: std::filesystem. There is an excellent answer from Shreevardhan below with this source code:

#include <string>
#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;

int main()
{
    std::string path = "/path/to/directory";
    for (const auto & entry : fs::directory_iterator(path))
        std::cout << entry.path() << std::endl;
}

Old Answer:

In small and simple tasks I do not use boost, I use dirent.h. It is available as a standard header in UNIX, and also available for Windows via a compatibility layer created by Toni Ronkko.

DIR *dir;
struct dirent *ent;
if ((dir = opendir ("c:\\src\\")) != NULL) {
  /* print all the files and directories within directory */
  while ((ent = readdir (dir)) != NULL) {
    printf ("%s\n", ent->d_name);
  }
  closedir (dir);
} else {
  /* could not open directory */
  perror ("");
  return EXIT_FAILURE;
}

It is just a small header file and does most of the simple stuff you need without using a big template-based approach like boost (no offence, I like boost!).

How to get the list of files in a directory in a shell script?

search_dir=/the/path/to/base/dir/
for entry in "$search_dir"/*
do
  echo "$entry"
done

Find file in directory from command line

find /root/directory/to/search -name 'filename.*'
# Directory is optional (defaults to cwd)

Standard UNIX globbing is supported. See man find for more information.

If you're using Vim, you can use:

:e **/filename.cpp

Or :tabn or any Vim command which accepts a filename.

Find all files in a directory with extension .txt in Python

You can use glob:

import glob, os
os.chdir("/mydir")
for file in glob.glob("*.txt"):
    print(file)

or simply os.listdir:

import os
for file in os.listdir("/mydir"):
    if file.endswith(".txt"):
        print(os.path.join("/mydir", file))

or if you want to traverse directory, use os.walk:

import os
for root, dirs, files in os.walk("/mydir"):
    for file in files:
        if file.endswith(".txt"):
             print(os.path.join(root, file))

Command to list all files in a folder as well as sub-folders in windows

The below post gives the solution for your scenario.

dir /s /b /o:gn

/S Displays files in specified directory and all subdirectories.

/B Uses bare format (no heading information or summary).

/O List by files in sorted order.

Then in :gn, g sorts by folders and then files, and n puts those files in alphabetical order.

How do you get a list of the names of all files present in a directory in Node.js?

You can use the fs.readdir or fs.readdirSync methods. fs is included in Node.js core, so there's no need to install anything.

fs.readdir

const testFolder = './tests/';
const fs = require('fs');

fs.readdir(testFolder, (err, files) => {
  files.forEach(file => {
    console.log(file);
  });
});

fs.readdirSync

const testFolder = './tests/';
const fs = require('fs');

fs.readdirSync(testFolder).forEach(file => {
  console.log(file);
});

The difference between the two methods, is that the first one is asynchronous, so you have to provide a callback function that will be executed when the read process ends.

The second is synchronous, it will return the file name array, but it will stop any further execution of your code until the read process ends.

How to find all files containing specific text (string) on Linux?

Do the following:

grep -rnw '/path/to/somewhere/' -e 'pattern'

-r or -R is recursive,
-n is line number, and
-w stands for match the whole word.
-l (lower-case L) can be added to just give the file name of matching files.
-e is the pattern used during the search

Along with these, --exclude, --include, --exclude-dir flags could be used for efficient searching:

This will only search through those files which have .c or .h extensions:

grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"

This will exclude searching all the files ending with .o extension:

grep --exclude=\*.o -rnw '/path/to/somewhere/' -e "pattern"

For directories it's possible to exclude one or more directories using the --exclude-dir parameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/:

grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"

This works very well for me, to achieve almost the same purpose like yours.

For more options, see man grep.