Question

我有如下文本文件（注意开头的空格）：

  aaaaaaaaaa
  abbbbbbbbbbb bbbbbbbbbb
 ccccccccccccc ccccccccccc cccccccccc
ddddddddddd ddd dddddd ddddd
eeeeeeeeeee

如何从每行的开头删除所有空格？

预期产出：

aaaaaaaaaa
abbbbbbbbbbb bbbbbbbbbb
ccccccccccccc ccccccccccc cccccccccc
ddddddddddd ddd dddddd ddddd
eeeeeeeeeee

我尝试使用ltrim()，但它似乎不起作用：

$liness = file('file.txt');
$lines = ltrim($liness);

file_put_contents('file.txt', implode($lines));
echo $lines;

Answer 1

好的$lines = array_map( 'ltrim', $liness ); file_put_contents( 'file.txt', implode($lines) );，但与echo：

一起使用

print_r()

并且，不要将foreach( $lines as $line ) echo "$line\n";用于数组，而是使用import java.util.*; class Loader { protected int BucketSize; protected int bucket; protected int price; public void SetBucketSize(int b) { Scanner input = new Scanner(System.in); System.out.println("What Bucket Size (1-5)?"); bucket = input.nextInt(); while (bucket <6) { System.out.println("Enter valid Bucket Size(1-5)"); } if (bucket == 1) { price = 100; } if (bucket == 2) { price = 200; } if (bucket == 3) { price = 300; } if (bucket == 4) { price = 400; } if (bucket == 5) { price = 500; } b = price; price = BucketSize; } public void GetBucketSize() { return this.BucketSize; } @Override public void setRentalProfit() { RentalProfit = (RentalRate * RentalDays); } @Override public String toString() { return "Tractor (Rental days = " + RentalDays + ", Rental Rate = " + RentalRate + ", Rental profit = " + RentalProfit + ", VehicleID = " + VehicleID + BucketSize + ")"; } }。或者：

Loader.java:46: error: incompatible types: unexpected return value
         return this.BucketSize;
                    ^
Loader.java:49: error: method does not override or implement a method from a supertype
    @Override
    ^
Loader.java:52: error: cannot find symbol
      RentalProfit = (RentalRate * RentalDays);  
      ^
  symbol:   variable RentalProfit
  location: class Loader
Loader.java:52: error: cannot find symbol
      RentalProfit = (RentalRate * RentalDays);  
                      ^
  symbol:   variable RentalRate
  location: class Loader
Loader.java:52: error: cannot find symbol
      RentalProfit = (RentalRate * RentalDays);  
                                   ^
  symbol:   variable RentalDays
  location: class Loader
Loader.java:57: error: cannot find symbol
        return  "Tractor (Rental days = " + RentalDays + ", Rental Rate = " + RentalRate +

详细了解array_map()

Answer 2

将文件读入数组，修剪每个数组元素并将其组合成一个字符串，将该字符串放回文件中：

trim(' a d  d d ');
//result: 'a d  d d', beginning and ending whitespaces removed

使用PHP 修剪功能。

ltrim()

还有rtrim()和grep -vE "^#"个功能可以删除左侧和右侧空格。

Answer 3

您只需使用trim()：

$lines = trim($liness);

From PHP Manual:

trim - 从字符串的开头和结尾去掉空格（或其他字符）

Answer 4

您需要逐行读取文件以进行修剪。

<?php
$file = fopen('yourfile', "r");
$new_file="";
if($file){
    while (($line = fgets($file)) !== false) { // read file one line at a time.
        $newfile .= ltrim($line); // trim it! trim it! :)
    }
    fclose($file);
    echo $newfile; // !Adios
} else die('Unable to redy the file. :(');

这是fiddle给你的

以其他方式在dom中读取文件并使用Reg-ex来精简“..”找到多个空格并仅用一个替换。

从每个数组元素的开头删除空格

4 个答案: