Undefined variable script - 版本历史

2013年12月18日 (三) 11:14 Shen

2013-12-18T11:14:27Z

←上一版本		2013年12月18日 (三) 11:14的版本
第5行：		第5行：
	exit		exit
	run it and it prints:		run it and it prints:
	this is tete		this is tete
	OK!		OK!
	second file (excutable):		second file (excutable):
			#
	#
	echo 'this is tete'		echo 'this is tete'
	echo $hi		echo $hi
	echo 'OK!'		echo 'OK!'
	exit		exit

	run it and it prints:		run it and it prints:
		⚫	this is tete

		⚫	hi: Undefined variable.
⚫	this is tete
⚫	hi: Undefined variable.

	Because 1st file have no "#"/"#!/bin/sh"/"#!/bin/csh" on the first line,		Because 1st file have no "#"/"#!/bin/sh"/"#!/bin/csh" on the first line,
	in most of the linux distributions, the default interpreter of a script is /bin/sh		in most of the linux distributions, the default interpreter of a script is /bin/sh

2013年12月18日 (三) 11:13 Shen

2013-12-18T11:13:46Z

←上一版本		2013年12月18日 (三) 11:13的版本
第1行：		第1行：
	first file (excutable):		first file (excutable):
			echo 'this is tete'

	echo ~~'this is tete'~~		echo $hi
	echo ~~$hi~~		echo 'OK!'
		⚫	exit
	echo 'OK!'
⚫	exit

	run it and it prints:		run it and it prints:

	this is tete		this is tete

	OK!		OK!

	second file (excutable):		second file (excutable):

	#		#
	echo 'this is tete'		echo 'this is tete'
	echo $hi		echo $hi
	echo 'OK!'		echo 'OK!'

2013年12月18日 (三) 11:12 Shen

2013-12-18T11:12:31Z

←上一版本		2013年12月18日 (三) 11:12的版本
第1行：		第1行：
	first file (excutable):		first file (excutable):

	echo 'this is tete'		echo 'this is tete'
	echo $hi		echo $hi
	echo 'OK!'		echo 'OK!'
	exit		exit

	run it and it prints:		run it and it prints:

	this is tete		this is tete

	OK!		OK!

	second file (excutable):		second file (excutable):

	#
			#
	echo 'this is tete'		echo 'this is tete'
	echo $hi		echo $hi
	echo 'OK!'		echo 'OK!'
	exit		exit

	run it and it prints:		run it and it prints:

	this is tete		this is tete
	hi: Undefined variable.		hi: Undefined variable.

Shen：以“first file (excutable): echo 'this is tete' echo $hi echo 'OK!' exit run it and it prints: this is tete OK! second file (excutable): # echo 'this is tete'...”为内容创建页面

2013-12-18T11:11:49Z

以“first file (excutable): echo 'this is tete' echo $hi echo 'OK!' exit run it and it prints: this is tete OK! second file (excutable): # echo 'this is tete'...”为内容创建页面

新页面

first file (excutable):
echo 'this is tete'
echo $hi
echo 'OK!'
exit
run it and it prints:
this is tete

OK!
second file (excutable):
#
echo 'this is tete'
echo $hi
echo 'OK!'
exit
run it and it prints:
this is tete
hi: Undefined variable.

Because 1st file have no "#"/"#!/bin/sh"/"#!/bin/csh" on the first line,
in most of the linux distributions, the default interpreter of a script is /bin/sh
if it is not specified, and /bin/sh DOES NOT think an undefined variable is a problem!
"#" will call csh, and print the problem.

Undefined variable script - 版本历史

2013年12月18日 (三) 11:14 Shen

2013年12月18日 (三) 11:13 Shen

2013年12月18日 (三) 11:12 Shen

Shen：​以“first file (excutable): echo 'this is tete' echo $hi echo 'OK!' exit run it and it prints: this is tete OK! second file (excutable): # echo 'this is tete'...”为内容创建页面

Shen：以“first file (excutable): echo 'this is tete' echo $hi echo 'OK!' exit run it and it prints: this is tete OK! second file (excutable): # echo 'this is tete'...”为内容创建页面