Скрипт IF EXIST

Помогите, пожалуйста написать скрипт по установке компонента Win7. Условие: если есть файл в директории, то запустить службу, если нет — запустить установку. Что-то начал воять, но даже не знаю на каком языке. Результата нет. Само собой, ведь программист из меня не оч) Заготовка:

Cmd Torrent exist .
Есть очень замечательная утилита WGet Но в наших сетях создали торрент трэкер чтобы обойти.

Paradox СУБД — Table does not exist. File or Directory does not exist
Создал базу данных в Paradox потом начал создавать СУБД, выдало ошибку Table does not exist. File.

Cmake does not exist
Уже очень долгое время не могу найти информацию по данной ошибке, английский немного знаю, читать.

IF EXIST — синтаксис
С чем может быть связано такое? Версия SQL server 2016. Microsoft SQL Server Management.

если ты админ или собираешься им стать,
то для подобных задач можно порекомендовать освоение Ansible
вместо ‘вояния’ на незнамо каком языке.

Решение

lacostewin, всё правильно.
Только переменную нужно раскрывать через знаки %
И скрипт запускать с повышенными привилегиями.
И немного поправить синтаксис.

Заказываю контрольные, курсовые, дипломные и любые другие студенческие работы здесь или здесь.

Shared memory does not exist
Доброе утро! Столкнулся с такой проблемой, Oracle 8.1, лет 20 крутится около 18 схем и начала.

File .prg does not exist
При попытке использовать любые функции или ключевые слова, кроме самых простых, типа «SELECT, FROM.

How can connect to DB that exist on Server when .
How can connect t DB that exist on Server, when my ASP Pages are existing on other Server. Two.

The flow pattern does not exist
Всем привет. суть вопроса проста. Мне необходимо создать Рандомный лист, с которым я буду в.

How to check if a file exists in a shell script

I’d like to write a shell script which checks if a certain file, archived_sensor_data.json , exists, and if so, deletes it. Following http://www.cyberciti.biz/tips/find-out-if-file-exists-with-conditional-expressions.html, I’ve tried the following:

However, this throws an error

when I try to run the resulting test_controller script using the ./test_controller command. What is wrong with the code?

5 Answers 5

You’re missing a required space between the bracket and -e :

Here is an alternative method using ls :

If you want to hide any output from ls so you only see yes or no, redirect stdout and stderr to /dev/null :

The backdrop to my solution recommendation is the story of a friend who, well into the second week of his first job, wiped half a build-server clean. So the basic task is to figure out if a file exists, and if so, let’s delete it. But there are a few treacherous rapids on this river:

Everything is a file.

Scripts have real power only if they solve general tasks

To be general, we use variables

We often use -f force in scripts to avoid manual intervention

And also love -r recursive to make sure we create, copy and destroy in a timely fashion.

Consider the following scenario:

We have the file we want to delete: filesexists.json

This filename is stored in a variable

We also hava a path variable to make things really flexible

So let’s see if -e does what it is supposed to. Does the files exist?

However, what would happen, if the file variable got accidentally be evaluated to nuffin’

What? It is supposed to return with an error. And this is the beginning of the story how that entire folder got deleted by accident

An alternative could be to test specifically for what we understand to be a ‘file’

So the file exists.

So this is not a file and maybe, we do not want to delete that entire directory

How to mkdir only if a directory does not already exist?

I am writing a shell script to run under the KornShell (ksh) on AIX. I would like to use the mkdir command to create a directory. But the directory may already exist, in which case I do not want to do anything. So I want to either test to see that the directory does not exist, or suppress the «File exists» error that mkdir throws when it tries to create an existing directory.

How can I best do this?

16 Answers 16

Note that this will also create any intermediate directories that don’t exist; for instance,

will create directories foo , foo/bar , and foo/bar/baz if they don’t exist.

Some implementation like GNU mkdir include mkdir —parents as a more readable alias, but this is not specified in POSIX/Single Unix Specification and not available on many common platforms like macOS, various BSDs, and various commercial Unixes, so it should be avoided.

If you want an error when parent directories don’t exist, and want to create the directory if it doesn’t exist, then you can test for the existence of the directory first:

This should work:

which will create the directory if it doesn’t exist, but warn you if the name of the directory you’re trying to create is already in use by something other than a directory.

Defining complex directory trees with one command

If you don’t want to show any error message:

If you want to show your own error message:

The old tried and true

will do what you want with none of the race conditions many of the other solutions have.

Sometimes the simplest (and ugliest) solutions are the best.

mkdir foo works even if the directory exists. To make it work only if the directory named «foo» does not exist, try using the -p flag.

This will create the directory named «foo» only if it does not exist. 🙂

mkdir does not support -p switch anymore on Windows 8+ systems.

You can use this:

You can either use an if statement to check if the directory exists or not. If it does not exits, then create the directory.

You can directory use mkdir with -p option to create a directory. It will check if the directory is not available it will.

mkdir -p also allows to create the tree structure of the directory. If you want to create the parent and child directories using same command, can opt mkdir -p

Or if you want to check for existence first:

-e is the exist test for KornShell.

You can also try googling a KornShell manual.

Referring to man page man mkdir for option — p

which will create all directories in a given path, if exists throws no error otherwise it creates all directories from left to right in the given path. Try the below command. the directories newdir and anotherdir doesn’t exists before issuing this command

Correct Usage

mkdir -p /tmp/newdir/anotherdir

After executing the command you can see newdir and anotherdir created under /tmp. You can issue this command as many times you want, the command always have exit(0) . Due to this reason most people use this command in shell scripts before using those actual paths.