写一个文件，如果存在则追加，否则在 bash 中创建
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write a file, append if it exists otherwise create in bash
提问by coolerking
Im trying to write a file with the content of a variable, but if the file doesnt exist create it:
我试图用变量的内容编写一个文件，但如果该文件不存在，请创建它：
So far i got this:
到目前为止，我得到了这个：
echo "$Logstring" >> $fileLog
What im missing because when the file doesnt exist theres an error. Is an if condition necessary?
我缺少什么，因为当文件不存在时会出现错误。if 条件是否必要？
采纳答案by Ярослав Рахматуллин
#! /bin/bash
VAR="something to put in a file"
OUT=
if [ ! -f "$OUT" ]; then
mkdir -p "`dirname \"$OUT\"`" 2>/dev/null
fi
echo $VAR >> $OUT
# the important step here is to make sure that the folder for the file exists
# and create it if it does not. It will remain silent if the folder exists.
$ sh out hello/how/are/you/file.out
geee: ~/src/bash/moo
$ sh out hello/how/are/you/file.out
geee: ~/src/bash/moo
$ sh out another/file/lol.hmz
geee: ~/src/bash/moo
$ find .
.
./out
./another
./another/file
./another/file/lol.hmz
./hello
./hello/how
./hello/how/are
./hello/how/are/you
./hello/how/are/you/file.out
geee: ~/src/bash/moo
$ cat ./hello/how/are/you/file.out
something to put in a file
something to put in a file
geee: ~/src/bash/moo
$ cat ./another/file/lol.hmz
something to put in a file
the escaped " for dirname are needed if the folder of file has spaces in the name.
如果文件的文件夹名称中有空格，则需要转义的 " 用于 dirname。
回答by user2085368
Use the touchcommand:
使用touch命令：
touch $fileLog
echo "$Logstring" >> $fileLog
