if file exists

[ -a file] is true if file exists. [ -b file] True if file exists and is a block special file. [ -c file] True if file exists and is a word special. [ -d file] True if file exists and is a directory. [ -e file] is true if file exists. [ -f file]

1. String judgmentSTR1 = str2 When two strings have the same content, length is trueStr1! = str2 True when string str1 and str2 are not equal-N str1 True when the length of the string is greater than 0 (string non-null)-Z str1 True when the string

The shell condition determines if the-Z to-D meaning[-A file] is true if file exists.[-B file] True if file exists and is a block special file.[-C file] True if file exists and is a word special.[-D file] True if file exists and is a directory.[-E

[-A file] is true if file exists.[-B file] True if file exists and is a block special file.[-C file] True if file exists and is a word special.[-D file] True if file exists and is a directory.[-E File] True if file exists.[-F file] True if file

Http://wenku.baidu.com/link?url=9Q9VU54XuvlN77urP1zwOLVMMrS2EFNx4HcvFizdPl-zQy3K_ Ipd3o-mdu4sbihezumnq0blbwhusuaol_y6quvkxtgjiaem9gq9i-jb5_e Shell in the condition to determine if in the-Z to-D meaning 2011-09-05 [-a file] if the file The existence

Objective:no matter what programming language is inseparable from conditional judgment. The shell is no exception. Copy Code code as follows: If List Then Do something here Elif List Then Do another thing Else Do something

Shell if judge commonly used in the green part, the tail part of the more do not understand. Reproduced from Baidu Library. [-A file] if FILE existence is true. [-B-file] True if file exists and is a block-specific file. [-C file] is true if file

Java EE Development of various types of resources download list, the history of the most complete IT resources, personal collection summary. Objective: No matter what programming language is inseparable from conditional judgment. The shell is no

(a) Conditions to determine if the meaning of-Z to-D[-A file] is true if file exists.[-B file] True if file exists and is a block special file.[-C file] True if file exists and is a special file of a word .　　[-D file] True if file exists and is a

The meaning of the-Z to-D in the conditional judgment in the shell [-A file] if FILE existence is true. [-B-file] True if file exists and is a block-specific file. [-C file] is true if file exists and is a word special file. [-D file] is true if

The meaning of the-Z to-D in the conditional judgment in the shell Copyright Notice: This article original articles for bloggers, repost please indicate the source. If in doubt, please contact me. I'll be appreciated.

Startup script start.sh This script is used to start the project, log logs and PID#!/bin/shprg=" $" #$ A represents the current startup script # Get the true path of the file while[-H"$PRG"]; Dols= ' Ls-ld"$PRG"' link= ' Expr"$ls": ' .*-> \ (. *\) $"

first, the numerical judgmentInt1-eq INT2 INT1 and INT2 two number equal true Int1-ne INT2 INT1 and INT2 two number of true int1-gt INT2 INT1 greater than INT1 for true int1-g e INT2 INT1 greater than or equal to INT2 trueInt1-lt INT2 INT1 Less than

Conditional judgment is the basis for a program to gain intelligence, while the Bourne shell script simulates conditional expressions in most programming languages by command.The control structures supported in the shell are:(1) If then else fi(2)

If condition judgment1. Basic syntax:if [command]; ThenStatements that meet the criteria for executionFi2. Extended syntax:if [command];thenStatements that meet the criteria for executionelif [Command];thenStatements that meet the criteria for

Conditional judgment statements are not necessary in any program writing, as is the case in shell programming, where the comparison operators that are often used in the shell's test commands are sorted into numeric comparisons, string comparisons,

In a structured command, the most basic type is the If-then statement if Commandthen Commandfibash the Shell's if statement executes the IF line definition of the command, and if the exit status code of the command is 0, then the command in the then

1. The first line must specify the shell used: #!/bin/bash/2, Print command: Echo-N: Suppress line breaks3. Use command line parameters:$#: The number of command-line arguments passed in the script$*: All command-line parameter values, with a space

1. string Judgments STR1 = str2 True when two strings have the same content, length Str1! = str2 True when strings str1 and str2 are unequal -N str1 True when the length of a string is

/// /// All operations on files/// Public class FileOption{/// /// Whether the deletion is successful/// /// Delete the entire file path /// whether the deletion is successful Public bool DeleteFile (string FileFullPath){Try{If (File. Exists