linux中变量IFS的使用
IFS和“=”之间不可以有空格 来源： https://www.cnblogs.com/ArChieve/p/11672106.html
ifs
When do I set IFS to a newline in Bash?
I thought setting IFS to $'\n' would help me in reading an entire file into an array, as in: IFS=$'\n' read -r -a array < file However, the above command only reads the first line of the file into the first element of the array, and nothing else. Even this reads only the first line into the array: string=$'one\ntwo\nthree' IFS=$'\n' read -r -a array <<< "$string" I came across other posts on this site that talk about either using mapfile -t or a read loop to read a file into an array. Now my question is: when do I use IFS=$'\n' at all? Your second try almost works, but you have to tell read
shell 内部域分隔IFS环境变量
shell 内部域分隔IFS环境变量: 1. data="name,sex,rollno,location" oldIFS=$IFS # 备份IFS到变量oldIFS IFS=$',' # 将IFS设置为逗号，便于做data的分隔符 IFS=$oldIFS # 最后将IFS还原 for item in $data;do echo Item:$item;done 2. data_code="name:sex:rollno:location" data_value="gender:certificate_type:certificate_no:birthday" OldIFS=$IFS IFS=':' array1=($data_code) array2=($data_value) IFS=$OldIFS for db_name in ${array1[@]} do echo $db_name done 来源： https://www.cnblogs.com/Arabi/p/11573802.html
揭秘外汇套路十部曲，IFS MARKETS炒外汇骗局曝光
▋文章摘要： 在 IFS MARKETS外汇被骗挽回损失咨询子雾法援；wq000015 帮你挽回损失！ IFS MARKETS 被骗了怎么办？ IFS MARKETS 被骗追回咨询子雾法援： wq000015 IFS MARKETS 赚钱不能平仓怎么办 ? IFS MARKETS 是黑平台吗 ? IFS MARKETS 老师恶意喊单怎么追回损失 ? IFS MARKETS 炒外汇 被骗亏损怎么办？ 外汇投资套路十部曲： 第一步： 加你微信，然后把你拉到一个股票交流群； 第二步： 告诉你这个群解散了，在拉入新的群 第三步： 在群里讨论股票，告诉你直播平台地址，给你直播账号，让你去学习股票技术知识，并提供牛股 第四步： 有大约几周都在讲股票 K线技术，提供牛股，分析技术指标 ，并免费提供他的技术指标文档，让你相信他，分享自己做公益的照片，反正就是把自己包装成一个大善人。再然后你会被从这个群里踢出来，然后拉入一个新的群，很不幸的告诉你，这个群里百分之八十都是托，只有那么很少一部分是他们需要攻下的客户，他会要求你截图股票账户信息，也就是你有多少钱，摸底你的资金量。 第五步： 股票大跌了，大家赶紧卖股票减少损失，卖完股票， 让 大家炒黄金， 外汇，指数 ， 数字货币 ，然后告诉你 近期 有大行情。 第六步： 你开户了，开户后，助理会不停的催促你入金，跟上老师的操作
What does IFS= do in this bash loop: `cat file | while IFS= read -r line; do … done`
I'm learning bash and I saw this construction: cat file | while IFS= read -r line; do ... done Can anyone explain what IFS= does? I know it's input field separator, but why is it being set to nothing? IFS does many things but you are asking about that particular loop. The effect in that loop is to preserve leading and trailing white space in line . To illustrate, first observe with IFS set to nothing: $ echo " this is a test " | while IFS= read -r line; do echo "=$line=" ; done = this is a test = The line variable contains all the white space it received on its stdin. Now, consider the same
shell脚本实现FTP自动上传文件
需求： 将某一目录下，文件名为*年_月_日*的文件上传到ftp服务器 ####本地的/home/shell_test/data/ to ftp服务器上的/home/vsftpd/test/test1/#### #!/bin/bash DATE=$(date +%Y_%m_%d) filenames=`ls /home/shell_test/data/|sed -n '/[0-9]\{4\}_[0-9]\{2\}_[0-9]\{2\}/p'` OLD_IFS="$IFS" IFS=" " arr=($filenames) IFS="$OLD_IFS" for s in ${arr[@]} do ftp -n<<! open 10.20.31.222 user test 123456 binary cd /home/vsftpd/test/test1/ lcd /home/shell_test/data/ prompt put $s close bye ! done 安装ftp服务器:https://blog.csdn.net/qq_26941173/article/details/54575952 cat /etc/vsftpd/vsftpd.conf # Example config file /etc/vsftpd/vsftpd.conf # # The default
Word splitting in Bash with IFS set to a non-whitespace character
I'm going through a Bash tutorial , and specifically the subject of word splitting. This script, called "args", helps demonstrate word splitting examples: #!/usr/bin/env bash printf "%d args:" $# printf " <%s>" "$@" echo An example: $ ./args hello world, here is "a string of text!" 5 args: <hello> <world,> <here> <is> <a string of text!> So far so good. I understand how this works. However, when I replace IFS with a non-whitespace character, say : , the script does not perform word splitting if I pass the string directly as an argument. $ ./args one:two:three 1 args: <one:two:three> However,
What does IFS= do in this bash loop: `cat file | while IFS= read -r line; do … done`
问题 I'm learning bash and I saw this construction: cat file | while IFS= read -r line; do ... done Can anyone explain what IFS= does? I know it's input field separator, but why is it being set to nothing? 回答1: IFS does many things but you are asking about that particular loop. The effect in that loop is to preserve leading and trailing white space in line . To illustrate, first observe with IFS set to nothing: $ echo " this is a test " | while IFS= read -r line; do echo "=$line=" ; done = this is
Word splitting in Bash with IFS set to a non-whitespace character
问题 I'm going through a Bash tutorial, and specifically the subject of word splitting. This script, called "args", helps demonstrate word splitting examples: #!/usr/bin/env bash printf "%d args:" $# printf " <%s>" "$@" echo An example: $ ./args hello world, here is "a string of text!" 5 args: <hello> <world,> <here> <is> <a string of text!> So far so good. I understand how this works. However, when I replace IFS with a non-whitespace character, say : , the script does not perform word splitting
What is the exact meaning of IFS=$'\\n'?
If the following example, which sets the IFS environment variable to a line feed character... IFS=$'\n' What does the dollar sign mean exactly ? What does it do in this specific case? Where can I read more on this specific usage (Google doesn't allow special characters in searches and I don't know what to look for otherwise)? I know what the IFS environment variable is, and what the \n character is (line feed), but why not just use the following form: IFS="\n" (which does not work)? For example, if I want to loop through every line of a file and want to use a for loop, I could do this: for