How to use PHP as a shell scripting language

We all know that PHP is a very good dynamic web development language (fast speed, short development cycle...). But only a few people realize that PHP can also be used as a language for writing Shell scripts. When PHP is used as a language for writing Shell scripts, it is not as powerful as Perl or Bash, but it has good advantages. Especially for people like me who are familiar with PHP but not very familiar with Perl.
To use PHP as a shell scripting language, you must compile PHP as binary CGI instead of Apache mode; PHP compiled into binary CGI mode has some security issues. For solutions, please refer to the PHP manual ( http://www.php.net).
You may feel uncomfortable writing Shell scripts at first, but you will get better gradually: the only difference between using PHP as a general dynamic web page writing language and as a Shell script language is that a Shell script needs to be written first Line life explains the program path of this script:
#!/usr/local/bin/php -q
We added the parameter "-1" after the PHP execution file, so that PHP will not output HTTPHeader ( If you still need to use the dynamic web page as a Web, then you need to use the header function to output HTTPHeader yourself). Of course, you still need to use PHP's opening and closing tags in the Shell script:
Now let's look at an example to better understand the use of PHP as a Shell scripting language:
#!/usr /local/bin/php -q
print("Hello, world!n");
?>
The above program will simply output "Hello, world!" to the monitor.
1. Pass the Shell script running parameters to PHP:
As a Shell script, you often add some parameters when running the program. When PHP is a Shell script, there is an embedded array "$argv", use "$ argv" array can easily read the parameters when the Shell script is running ("$argv[1]" corresponds to the first parameter, "$argv[2]" corresponds to the second parameter, and so on) . For example, the following program:
#!/usr/local/bin/php -q
$first_name = $argv[1];
$last_name = $argv[2];
printf(" Hello, %s %s! How are you today?n", $first_name, $last_name);
?>
The above code requires two parameters when running, namely last name and first name, such as Run like this:
[dbrogdon@artemis dbrogdon]$ scriptname.ph Darrell Brogdon
The Shell script will output on the monitor:
Hello, Darrell Brogdon! How are you today?
[dbrogdon@artemis dbrogdon]$
When PHP is used as a dynamic web page writing language, it also contains the "$argv" array, but there are some differences from here: when PHP is used as a Shell script language, "$argv[0]" corresponds to the script The file name, and when used for dynamic web page writing, "$argv[1]" corresponds to the first parameter of QueryString.
2. Write an interactive Shell script:
If a Shell script just runs by itself and loses interactivity, then it is meaningless. When PHP is used to write Shell scripts, how to read the information entered by the user? Unfortunately, PHP itself does not have a function or method for reading user input information, but we can follow the example of other languages ​​and write a function "read" that reads user input information:
function read() {
$fp = fopen('/dev/stdin', 'r');
$input = fgets($fp, 255);
fclose($fp);
return $input;
}
?>
It should be noted that the above function can only be used on Unix systems (other systems need to make corresponding changes). The above function will open a file pointer, then read a line of no more than 255 bytes (that's what fgets does), then close the file pointer and return the read information.
Now we can use the function "read" to modify the program 1 we wrote earlier to make it more "interactive":
#!/usr/local/bin/php -q
function read() {
$fp = fopen('/dev/stdin', 'r');
$input = fgets($fp, 255);
fclose($fp);
return $input;
}
print("What is your first name? ");
$first_name = read();
print("What is your last name? ");
$last_name = read();
print("nHello, $first_name $last_name! Nice to meet you!n");
?>
Save the above program and run it, you You may see something unexpected: the last line of input becomes three lines! This is because the information returned by the "read" function also includes the ending newline character "n" of each line of the user, which is retained in the last name and first name. To remove the ending newline character, the "read" function needs to be modified:
function read() {
$fp = fopen('/dev/stdin', 'r');
$input = fgets($fp, 255);
fclose($fp);
$input = chop($input); // Remove trailing blanks
return $input;
}
?>
3. Include Shell scripts written in PHP in other languages Script:
Sometimes we may need to include Shell scripts written in PHP in Shell scripts written in other languages. It's actually very simple. Here is a simple example:
#!/bin/bash
echo This is the Bash section of the code.
/usr/local/bin/php -q << EOF
print("This is the PHP section of the coden");
?>
EOF
actually calls PHP to parse the following code and then output it; then, try the following Code:
#!/bin/bash
echo This is the Bash section of the code.
/usr/local/bin/php -q << EOF
$myVar = ' PHP';
print("This is the $myVar section of the coden");
?>
EOF
It can be seen that the only difference between the two codes is that it is used the second time Try running a variable "$myVar", and PHP actually gives an error message: "Parse error: parse error in - on line 2"! This is because the variables in Bash are also "$myVar", and the Bash parser replaces the variables first. To solve this problem, you need to add "" in front of each PHP variable. escape character, then the code just now is modified as follows:
#!/bin/bash
echo This is the Bash section of the code.
/usr/local/bin/php -q << EOF
$myVar = 'PHP';
print("This is the $myVar section of the coden");
?>
EOF
Okay, now you can use PHP It's time to write your own shell script, I hope you are doing well.

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The above introduces how to use PHP as a Shell script language, including aspects of it. I hope it will be helpful to friends who are interested in PHP tutorials.