19.1. Using exec

An exec <filename command redirects stdin to a file. From that point on, all stdin comes from that file, rather than its normal source (usually keyboard input). This provides a method of reading a file line by line and possibly parsing each line of input using sed and/or awk.

Example 19-1. Redirecting stdin using exec

#!/bin/bash
# Redirecting stdin using 'exec'.


exec 6<&0          # Link file descriptor #6 with stdin.
                   # Saves stdin.

exec < data-file   # stdin replaced by file "data-file"

read a1            # Reads first line of file "data-file".
read a2            # Reads second line of file "data-file."

echo
echo "Following lines read from file."
echo "-------------------------------"
echo $a1
echo $a2

echo; echo; echo

exec 0<&6 6<&-
#  Now restore stdin from fd #6, where it had been saved,
#+ and close fd #6 ( 6<&- ) to free it for other processes to use.
#
# <&6 6<&-    also works.

echo -n "Enter data  "
read b1  # Now "read" functions as expected, reading from normal stdin.
echo "Input read from stdin."
echo "----------------------"
echo "b1 = $b1"

echo

exit 0

Similarly, an exec >filename command redirects stdout to a designated file. This sends all command output that would normally go to stdout to that file.

Important	

exec N > filename affects the entire script or current shell. Redirection in the PID of the script or shell from that point on has changed. However . . .

N > filename affects only the newly-forked process, not the entire script or shell.

Thank you, Ahmed Darwish, for pointing this out.

text

1

An exec <filename command redirects stdin to a file

19.1. Using exec

An exec <filename command redirects stdin to a file. From that point on, all stdin comes from that file, rather than its normal source (usually keyboard input). This provides a method of reading a file line by line and possibly parsing each line of input using sed and/or awk.

Example 19-1. Redirecting stdin using exec

#!/bin/bash
# Redirecting stdin using 'exec'.


exec 6<&0          # Link file descriptor #6 with stdin.
                   # Saves stdin.

exec < data-file   # stdin replaced by file "data-file"

read a1            # Reads first line of file "data-file".
read a2            # Reads second line of file "data-file."

echo
echo "Following lines read from file."
echo "-------------------------------"
echo $a1
echo $a2

echo; echo; echo

exec 0<&6 6<&-
#  Now restore stdin from fd #6, where it had been saved,
#+ and close fd #6 ( 6<&- ) to free it for other processes to use.
#
# <&6 6<&-    also works.

echo -n "Enter data  "
read b1  # Now "read" functions as expected, reading from normal stdin.
echo "Input read from stdin."
echo "----------------------"
echo "b1 = $b1"

echo

exit 0

Similarly, an exec >filename command redirects stdout to a designated file. This sends all command output that would normally go to stdout to that file.

Important	

exec N > filename affects the entire script or current shell. Redirection in the PID of the script or shell from that point on has changed. However . . .

N > filename affects only the newly-forked process, not the entire script or shell.

Thank you, Ahmed Darwish, for pointing this out.

copy | embed

• <filename, 
• a, 
• an, 
• command, 
• exec, 
• file, 
• redirects, 
• stdin, 
• to

#!/bin/bash
for file in *.groovy
do
  echo "Traitement de $file ..."
  sed -e "s/string1/string2/g" "$file" > "$file".tmp && mv -f "$file".tmp "$file"
done

bash

1

replace string in files

#!/bin/bash
for file in *.groovy
do
  echo "Traitement de $file ..."
  sed -e "s/string1/string2/g" "$file" > "$file".tmp && mv -f "$file".tmp "$file"
done

copy | embed

• bash, 
• file, 
• sed

#include <iostream>
#include <fstream>
using namespace std;

int main ()
{
    char data;
    fstream inFile, outFile;
    inFile.open ("A.txt", ios::in);
    if (inFile.fail())
    {
        cout << "File not found!" << endl;
    }
    else
    {

        outFile.open("C.txt", ios::out);
        while (!inFile.eof())
        {
            inFile.get(data);
            if (data==';')
            {
                data=',';
                outFile<<data;
            }
            else
                outFile<<data;
        }
        cout<<"Done.";
    }
    outFile.close();
    inFile.close();
}

cpp

1

file operations delimiter changer

#include <iostream>
#include <fstream>
using namespace std;

int main ()
{
    char data;
    fstream inFile, outFile;
    inFile.open ("A.txt", ios::in);
    if (inFile.fail())
    {
        cout << "File not found!" << endl;
    }
    else
    {

        outFile.open("C.txt", ios::out);
        while (!inFile.eof())
        {
            inFile.get(data);
            if (data==';')
            {
                data=',';
                outFile<<data;
            }
            else
                outFile<<data;
        }
        cout<<"Done.";
    }
    outFile.close();
    inFile.close();
}

copy | embed

• delimiter, 
• file, 
• i/o

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main ()
{
    string data;
    cout<<"Enter data: ";
    getline(cin,data);
    ofstream outFile; 
    outFile.open ("B.txt"); //open text file
    string::iterator pos;
    for (pos = data.begin(); pos != data.end(); pos++)
    {
        if (*pos==';') //check if character is ';'
        outFile<<endl;
        else
        outFile<<*pos;
    }
    outFile.close();
}

cpp

1

file operations ; delimited output

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main ()
{
    string data;
    cout<<"Enter data: ";
    getline(cin,data);
    ofstream outFile; 
    outFile.open ("B.txt"); //open text file
    string::iterator pos;
    for (pos = data.begin(); pos != data.end(); pos++)
    {
        if (*pos==';') //check if character is ';'
        outFile<<endl;
        else
        outFile<<*pos;
    }
    outFile.close();
}

copy | embed

• delimited, 
• file, 
• i/o, 
• output

#include <iostream>
#include <fstream>
using namespace std;

int main ()
{
    char data;
    ifstream inFile;
    inFile.open ("A.txt"); //open text file
    if (inFile.fail()) //check if file is found
    {
        cout << "File not found!" << endl;
    }
    while (!inFile.eof()) //check if it is end of file
    {
        inFile.get(data);
        if (data==';') //check for ';', if true goto next line
            cout<<endl;
        else  //else cout character
            cout<<data;
    }
    inFile.close();
}

cpp

1

file operations ; delimited

#include <iostream>
#include <fstream>
using namespace std;

int main ()
{
    char data;
    ifstream inFile;
    inFile.open ("A.txt"); //open text file
    if (inFile.fail()) //check if file is found
    {
        cout << "File not found!" << endl;
    }
    while (!inFile.eof()) //check if it is end of file
    {
        inFile.get(data);
        if (data==';') //check for ';', if true goto next line
            cout<<endl;
        else  //else cout character
            cout<<data;
    }
    inFile.close();
}

copy | embed

• delimiter, 
• file, 
• i/o

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    ifstream inFile;

    inFile.open("test1.txt");

    if (inFile.fail())       //check for file existence
    {
       cout << "File does not exist!" << endl;
       cout << "Program exits." << endl;
       cin.get();
       return 0;
    }

    //read  data
    char ch1;
    int num;

    while (!inFile.eof())    //continue to read and display on screen until EOF
    {
        inFile>>ch1>>num; 
        if (ch1=='P')
        cout<<ch1<<num<<endl;
    }

    inFile.close();
    cin.get();              // pause to show screen output
    return 0;
}

cpp

1

read admin number

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    ifstream inFile;

    inFile.open("test1.txt");

    if (inFile.fail())       //check for file existence
    {
       cout << "File does not exist!" << endl;
       cout << "Program exits." << endl;
       cin.get();
       return 0;
    }

    //read  data
    char ch1;
    int num;

    while (!inFile.eof())    //continue to read and display on screen until EOF
    {
        inFile>>ch1>>num; 
        if (ch1=='P')
        cout<<ch1<<num<<endl;
    }

    inFile.close();
    cin.get();              // pause to show screen output
    return 0;
}

copy | embed

• file, 
• i/o

<?php 
$i = 1;
$files = get_field_duplicate('pres_file'); 
foreach ($files as $file) { ?>

<a href="<?php echo $file; ?>">Presentation <?php echo $i++ ?></a>
 <br />
<?php   
}
?>

php

1

Magicfields duplicate file fields

<?php 
$i = 1;
$files = get_field_duplicate('pres_file'); 
foreach ($files as $file) { ?>

<a href="<?php echo $file; ?>">Presentation <?php echo $i++ ?></a>
 <br />
<?php   
}
?>

copy | embed

• file, 
• foreach, 
• magicfields, 
• wordpress

<?
header("content-type: $mime_type");
header("content-disposition: attachment; filename=$file_name");
header("cache-control: private");
header("pragma: private");
echo $file_data;
?>

php

1

Prompt user to 'open' or 'save' file when delivering dynamic file data with PHP

<?
header("content-type: $mime_type");
header("content-disposition: attachment; filename=$file_name");
header("cache-control: private");
header("pragma: private");
echo $file_data;
?>

copy | embed

• download, 
• file, 
• headers, 
• http, 
• php

<?
// $_FILES array
// $_FILES['field_name']['name'] = filename
// $_FILES['field_name']['type'] = mime type, if provided by browser
// $_FILES['field_name']['size'] = file size in bytes
// $_FILES['field_name']['tmp_name'] = temp file name / location
// $_FILES['field_name']['error'] = error code

if(is_uploaded_file($_FILES['field_name']['tmp_name'])) {
   $file = file_get_contents($_FILES['field_name']['tmp_name']);
   // do something with $file
}
?>

php

1

Uploaded file handling with PHP

<?
// $_FILES array
// $_FILES['field_name']['name'] = filename
// $_FILES['field_name']['type'] = mime type, if provided by browser
// $_FILES['field_name']['size'] = file size in bytes
// $_FILES['field_name']['tmp_name'] = temp file name / location
// $_FILES['field_name']['error'] = error code

if(is_uploaded_file($_FILES['field_name']['tmp_name'])) {
   $file = file_get_contents($_FILES['field_name']['tmp_name']);
   // do something with $file
}
?>

copy | embed

• file, 
• php, 
• upload

if( access( fname, F_OK ) != -1 ) 
{
    return(TRUE);
}

else 
{
    return(FALSE);
}

c

1

check for file existence

if( access( fname, F_OK ) != -1 ) 
{
    return(TRUE);
}

else 
{
    return(FALSE);
}

copy | embed

• c, 
• file

<?php
// FILE lib/model/Model.php:
class Model
{
  /**
   * Returns the abs path to a subdir of uploads specific for this model.
   *
   * If given a $path, it will be concatenated at the end.
   *
   * @param string $path optional relative path of a file inside the dir
   * @return string      complete path to subdir or file
   */
  public function getUploadPath($path = NULL)
  {
    return sfConfig::get('sf_upload_dir').'/event/' . $path;
  }

  /**
   * Returns abs path relative to the docroot.
   *
   * @param string $path
   * @return string
   */
  public function getWebPath($path = NULL)
  {
    return str_replace(sfConfig::get('sf_web_dir'), '', $this->getUploadPath($path));
  }
}

// FILE lib/form/ModelForm.php:
class ModelForm extends sfPropelForm
{
  public function configure() {}

  /** 
   * Loops through all form values, updates all files values to be absolute paths relative to the docroot.
   * Calls $model->getWebPath(), but the code is otherwise generally re-usable.
   *  
   * (non-PHPdoc)
   * @see symfony/plugins/sfPropelPlugin/lib/form/sfFormPropel#updateObject($values)
   */
  public function updateObject($values = null)
  {
    $object = parent::updateObject($values);
    foreach ($this->values as $field => $value)
    {
      if ($value instanceof sfValidatedFile)
      {
        $column = call_user_func(array(constant(get_class($object).'::PEER'), 'translateFieldName'), $field, BasePeer::TYPE_FIELDNAME, BasePeer::TYPE_PHPNAME);
        $getter = 'get'.$column;
        $setter = 'set'.$column;
        $object->$setter($object->getWebPath($object->$getter()));
      }
    }
    return $object;
  }
}
?>

php

1

File uploads in Symfony 1.2, my take

<?php
// FILE lib/model/Model.php:
class Model
{
  /**
   * Returns the abs path to a subdir of uploads specific for this model.
   *
   * If given a $path, it will be concatenated at the end.
   *
   * @param string $path optional relative path of a file inside the dir
   * @return string      complete path to subdir or file
   */
  public function getUploadPath($path = NULL)
  {
    return sfConfig::get('sf_upload_dir').'/event/' . $path;
  }

  /**
   * Returns abs path relative to the docroot.
   *
   * @param string $path
   * @return string
   */
  public function getWebPath($path = NULL)
  {
    return str_replace(sfConfig::get('sf_web_dir'), '', $this->getUploadPath($path));
  }
}

// FILE lib/form/ModelForm.php:
class ModelForm extends sfPropelForm
{
  public function configure() {}

  /** 
   * Loops through all form values, updates all files values to be absolute paths relative to the docroot.
   * Calls $model->getWebPath(), but the code is otherwise generally re-usable.
   *  
   * (non-PHPdoc)
   * @see symfony/plugins/sfPropelPlugin/lib/form/sfFormPropel#updateObject($values)
   */
  public function updateObject($values = null)
  {
    $object = parent::updateObject($values);
    foreach ($this->values as $field => $value)
    {
      if ($value instanceof sfValidatedFile)
      {
        $column = call_user_func(array(constant(get_class($object).'::PEER'), 'translateFieldName'), $field, BasePeer::TYPE_FIELDNAME, BasePeer::TYPE_PHPNAME);
        $getter = 'get'.$column;
        $setter = 'set'.$column;
        $object->$setter($object->getWebPath($object->$getter()));
      }
    }
    return $object;
  }
}
?>

copy | embed

• 1.2, 
• file, 
• symfony, 
• upload

package buildfromcbd;
//
import java.awt.Toolkit;
import java.awt.datatransfer.*;
import java.io.*;
//
public class Main {
    //this will be where we split up our values
    private static final String VALUE_SEPARATOR = ":::";
    //
    public static void main(String[] args) throws IOException, UnsupportedFlavorException
    {
       build();
    }
   public static String getClipboard() throws UnsupportedFlavorException, IOException {
       // here we grab the contents of the clipboard
        Transferable tran = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null);
        try {
            if (tran != null && tran.isDataFlavorSupported(DataFlavor.stringFlavor)) {
                String text = (String)tran.getTransferData(DataFlavor.stringFlavor);
                return text;
            }
        } catch (UnsupportedFlavorException e) {
            return "CBD_BUILD_FAILED.txt::: Could not build file, JAVA error report as fallows:\n\n"+e;
        } catch (IOException e) {
             return "CBD_BUILD_FAILED.txt::: Could not build file, JAVA error report as fallows:\n\n"+e;
        }
        return null;
    }
    public static void build()throws IOException, UnsupportedFlavorException
    {
        Writer output = null;
        String text = getClipboard();
        String[] cbd = parseCBD(text);
        //so our fist value will be our file name
        File file = new File(cbd[0]);
        //lets get our file open for writing now
        output = new BufferedWriter(new FileWriter(file));
        //if cbd has a second value lets write it to our files contents
        if(cbd.length>1)
        {
            output.write(cbd[1]);
        }else{
             // if we don't have a second value lets print "EMPTY :(" in our file
            output.write("EMPTY :(");
        }
        output.close();
    }
    public static String[] parseCBD(String cb_txt)
    {
        //let's sperate our values out
        String[] cbd = cb_txt.split(VALUE_SEPARATOR);
        //in this function you could do more than just split the data, get creative :)
        return cbd;
    }
}

java

1

Make file from clipboard data

package buildfromcbd;
//
import java.awt.Toolkit;
import java.awt.datatransfer.*;
import java.io.*;
//
public class Main {
    //this will be where we split up our values
    private static final String VALUE_SEPARATOR = ":::";
    //
    public static void main(String[] args) throws IOException, UnsupportedFlavorException
    {
       build();
    }
   public static String getClipboard() throws UnsupportedFlavorException, IOException {
       // here we grab the contents of the clipboard
        Transferable tran = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null);
        try {
            if (tran != null && tran.isDataFlavorSupported(DataFlavor.stringFlavor)) {
                String text = (String)tran.getTransferData(DataFlavor.stringFlavor);
                return text;
            }
        } catch (UnsupportedFlavorException e) {
            return "CBD_BUILD_FAILED.txt::: Could not build file, JAVA error report as fallows:\n\n"+e;
        } catch (IOException e) {
             return "CBD_BUILD_FAILED.txt::: Could not build file, JAVA error report as fallows:\n\n"+e;
        }
        return null;
    }
    public static void build()throws IOException, UnsupportedFlavorException
    {
        Writer output = null;
        String text = getClipboard();
        String[] cbd = parseCBD(text);
        //so our fist value will be our file name
        File file = new File(cbd[0]);
        //lets get our file open for writing now
        output = new BufferedWriter(new FileWriter(file));
        //if cbd has a second value lets write it to our files contents
        if(cbd.length>1)
        {
            output.write(cbd[1]);
        }else{
             // if we don't have a second value lets print "EMPTY :(" in our file
            output.write("EMPTY :(");
        }
        output.close();
    }
    public static String[] parseCBD(String cb_txt)
    {
        //let's sperate our values out
        String[] cbd = cb_txt.split(VALUE_SEPARATOR);
        //in this function you could do more than just split the data, get creative :)
        return cbd;
    }
}

copy | embed

• clipboard, 
• communication, 
• create, 
• data, 
• file, 
• generate, 
• make

Public Sub WriteLog(Message As String)

  Dim fso, fileName As String, logString As String, f as Integer
  
  fileName = App.path & "\Log_" & Format(Now, "yyyymmdd") & ".txt"
  logString = Format(Now, "hh:mm:ss") & " - " & Message
  f = Freefile
  Open fileName For Append As #f
  Print #f, logString
  Close #f

End Sub

vb.net

1

VB6: Write a message in a daily log

Public Sub WriteLog(Message As String)

  Dim fso, fileName As String, logString As String, f as Integer
  
  fileName = App.path & "\Log_" & Format(Now, "yyyymmdd") & ".txt"
  logString = Format(Now, "hh:mm:ss") & " - " & Message
  f = Freefile
  Open fileName For Append As #f
  Print #f, logString
  Close #f

End Sub

copy | embed

• file, 
• log, 
• vb6

import sys
import re
from sets import Set

f = open ('/Users/user/Downloads/PM-1.txt')

pm_match = re.compile (r'\d+_(\S+)')
pms = set()
unique = set()

for line in f.readlines(): 
     pm_result = pm_match.match (line.rstrip())
     
     if pm_result:
        pms.add(pm_result.group(1))
       
        
        
f.close()

#print pms

matchobj = re.compile (r'(\S+):\s+\d+\.\d+')

f_match = re.compile (r'f_(\d+)[a-z]+_\w+')

a_match = re.compile (r'a4_([0-9a-z]+)_\w+')

for line in sys.stdin:
    names = line.split("\t")

    output = ""
    for name in names:
        result = matchobj.match (name)
        
        if result:

            #print result.group(1)
            f_result = f_match.match (result.group(1))
            if f_result:
                PM_name = "fc1f" + f_result.group(1)
                
                if PM_name in pms:
                    unique.add(PM_name)          
            
            
            a_result = a_match.match (result.group(1))
            if a_result:
                PM_name = "anke4-" + a_result.group(1)
                
                if PM_name in pms:
                    unique.add(PM_name)

print len(unique)
    #print output.rstrip()

python

1

match my PM list to Hanno's TETRA results

import sys
import re
from sets import Set

f = open ('/Users/user/Downloads/PM-1.txt')

pm_match = re.compile (r'\d+_(\S+)')
pms = set()
unique = set()

for line in f.readlines(): 
     pm_result = pm_match.match (line.rstrip())
     
     if pm_result:
        pms.add(pm_result.group(1))
       
        
        
f.close()

#print pms

matchobj = re.compile (r'(\S+):\s+\d+\.\d+')

f_match = re.compile (r'f_(\d+)[a-z]+_\w+')

a_match = re.compile (r'a4_([0-9a-z]+)_\w+')

for line in sys.stdin:
    names = line.split("\t")

    output = ""
    for name in names:
        result = matchobj.match (name)
        
        if result:

            #print result.group(1)
            f_result = f_match.match (result.group(1))
            if f_result:
                PM_name = "fc1f" + f_result.group(1)
                
                if PM_name in pms:
                    unique.add(PM_name)          
            
            
            a_result = a_match.match (result.group(1))
            if a_result:
                PM_name = "anke4-" + a_result.group(1)
                
                if PM_name in pms:
                    unique.add(PM_name)

print len(unique)
    #print output.rstrip()

copy | embed

• file, 
• regexp, 
• set

<?php
/**
 * Log PHP's error into separate files. Recommended for use in production site.
 * Should be used in set_error_handler() to handle certain PHP errors (i.e. E_STRICT).
 * @link http://www.php.net/manual/en/function.set-error-handler.php Reference
 */
function errorHandler($errno, $errstr, $errfile=NULL, $errline=NULL, $errcontext=NULL) {
  // Log uncategorized errors
  if (is_null($errfile)) {
    $errfile = 'errors.log';
  }

  // Reconstruct the path
  // define('APP_DIR', '/my/application/')
  // define('LOG_DIR', '/log_dir/')
  // E.g. /my/application/controller/index.php -> /log_dir/controller/index.php
  $pos = strpos($errfile, APP_DIR);
  if ($pos !== FALSE) {
    // Strip off the application directory and attach log directory
    $errfile = LOG_DIR.substr($errfile, $pos + strlen(CMS_ROOT));
  }
  else {
    $errfile = LOG_DIR.$errfile; // E.g. /log_dir/errors.log
  }
  $dir = dirname($errfile);
  // Create dir if necessary
  if (! file_exists($dir)) {
    mkdir($dir, 0775, TRUE);
  }
  
  $logFile = fopen($errfile, 'a');
  fwrite($logFile, date('Y-m-d H:i:s ').$errstr);
  if ($errline) fwrite($logFile, " on line $errline");
  fwrite($logFile, "\n");
  fclose($logFile);
  
  if (PRODUCTION_SITE) // Prevent err msg from being printed out (log errors silently)
    return TRUE;

  return FALSE;
}
?>

php

1

Log errors in diffent folders/files reflecting the application folder structure.

<?php
/**
 * Log PHP's error into separate files. Recommended for use in production site.
 * Should be used in set_error_handler() to handle certain PHP errors (i.e. E_STRICT).
 * @link http://www.php.net/manual/en/function.set-error-handler.php Reference
 */
function errorHandler($errno, $errstr, $errfile=NULL, $errline=NULL, $errcontext=NULL) {
  // Log uncategorized errors
  if (is_null($errfile)) {
    $errfile = 'errors.log';
  }

  // Reconstruct the path
  // define('APP_DIR', '/my/application/')
  // define('LOG_DIR', '/log_dir/')
  // E.g. /my/application/controller/index.php -> /log_dir/controller/index.php
  $pos = strpos($errfile, APP_DIR);
  if ($pos !== FALSE) {
    // Strip off the application directory and attach log directory
    $errfile = LOG_DIR.substr($errfile, $pos + strlen(CMS_ROOT));
  }
  else {
    $errfile = LOG_DIR.$errfile; // E.g. /log_dir/errors.log
  }
  $dir = dirname($errfile);
  // Create dir if necessary
  if (! file_exists($dir)) {
    mkdir($dir, 0775, TRUE);
  }
  
  $logFile = fopen($errfile, 'a');
  fwrite($logFile, date('Y-m-d H:i:s ').$errstr);
  if ($errline) fwrite($logFile, " on line $errline");
  fwrite($logFile, "\n");
  fclose($logFile);
  
  if (PRODUCTION_SITE) // Prevent err msg from being printed out (log errors silently)
    return TRUE;

  return FALSE;
}
?>

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• debug, 
• error, 
• errorhandler, 
• file, 
• folder, 
• logging, 
• php

# Find process associated with a port

$ fuser 80/tcp
80/tcp:                802   803   804   806   807   808   809   810   811   812   813 23556 23561 23562 23563 23564 23565 23566 23567 23568 28574

# Find process and users associated with a port

$ fuser -nu tcp 80
80/tcp:                802(apache)   803(apache)   804(apache)   806(apache)   807(apache)   808(apache)   809(apache)   810(apache)   811(apache)   812(apache)   813(apache) 23556(root) 23561(apache) 23562(apache) 23563(apache) 23564(apache) 23565(apache) 23566(apache) 23567(apache) 23568(apache) 28574(apache)

# Kills a process that is locking a file. Useful when you're trying to unmount a volume and other sticky situations where a rogue process is annoying the hell out of you.

$ fuser -k /tmp/blocked_file

bash

1

Usage of Unix fuser

# Find process associated with a port

$ fuser 80/tcp
80/tcp:                802   803   804   806   807   808   809   810   811   812   813 23556 23561 23562 23563 23564 23565 23566 23567 23568 28574

# Find process and users associated with a port

$ fuser -nu tcp 80
80/tcp:                802(apache)   803(apache)   804(apache)   806(apache)   807(apache)   808(apache)   809(apache)   810(apache)   811(apache)   812(apache)   813(apache) 23556(root) 23561(apache) 23562(apache) 23563(apache) 23564(apache) 23565(apache) 23566(apache) 23567(apache) 23568(apache) 28574(apache)

# Kills a process that is locking a file. Useful when you're trying to unmount a volume and other sticky situations where a rogue process is annoying the hell out of you.

$ fuser -k /tmp/blocked_file

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• file, 
• fuser, 
• kill, 
• port, 
• user

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class SlugTester {
    static String FILENAME = "C:\\slug-test.txt";
    public static void main(String[] args)  {

        try  {
            BufferedReader reader = new BufferedReader(new FileReader(FILENAME));
            String line;
            while ((line = reader.readLine()) != null)  {
                System.out.println(line);
            }
        }

        catch (FileNotFoundException e)  {
            e.printStackTrace();
        }
        catch (IOException e)  {
            e.printStackTrace();
        }
    }
}

java

1

Print a file line for line in Java (the 1.6 way)

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class SlugTester {
    static String FILENAME = "C:\\slug-test.txt";
    public static void main(String[] args)  {

        try  {
            BufferedReader reader = new BufferedReader(new FileReader(FILENAME));
            String line;
            while ((line = reader.readLine()) != null)  {
                System.out.println(line);
            }
        }

        catch (FileNotFoundException e)  {
            e.printStackTrace();
        }
        catch (IOException e)  {
            e.printStackTrace();
        }
    }
}

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• bufferedreader, 
• file, 
• java, 
• print

<?php
header("Content-type: application/octet-stream");

// displays progress bar when downloading (credits to Felix ;-))
header("Content-Length: " . filesize('myImage.jpg'));
 
// file name of download file
header('Content-Disposition: attachment; filename="myImage.jpg"');
 
// reads the file on the server
readfile('myImage.jpg');

php

1

Force file download

<?php
header("Content-type: application/octet-stream");

// displays progress bar when downloading (credits to Felix ;-))
header("Content-Length: " . filesize('myImage.jpg'));
 
// file name of download file
header('Content-Disposition: attachment; filename="myImage.jpg"');
 
// reads the file on the server
readfile('myImage.jpg');

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• download, 
• file, 
• php

To get access to underlying stream (filelike) object in Python's logging system:

logger.handlers[0].stream

You'll have to figure out which handler for a logger object you want. I've only got one in my sample code. This snipt allows one to pass this stream object into interfaces that are expecting a file object.

python

1

File object for logging loggers

To get access to underlying stream (filelike) object in Python's logging system:

logger.handlers[0].stream

You'll have to figure out which handler for a logger object you want. I've only got one in my sample code. This snipt allows one to pass this stream object into interfaces that are expecting a file object.

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• file, 
• logging, 
• stream

grep -r 'public static void main(' .

#will do the same thing. In fact, you can also use

grep -rI 'public static void main(' .

#for searching only text files. And if you only want to list the files without the matching content, use

grep -rI –files-without-matches 'public static void main(' .

bash

1

Search file by content (improved)

grep -r 'public static void main(' .

#will do the same thing. In fact, you can also use

grep -rI 'public static void main(' .

#for searching only text files. And if you only want to list the files without the matching content, use

grep -rI –files-without-matches 'public static void main(' .

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• bash, 
• file, 
• find, 
• grep, 
• linux, 
• search