bash 使用bash脚本修改配置文件
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原文地址: http://stackoverflow.com/questions/2464760/
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Modify config file using bash script
提问by Progress Programmer
I'm writing a bash script to modify a config file which contains a bunch of key/value pairs. How can I read the key and find the value and possibly modify it?
我正在编写一个 bash 脚本来修改包含一堆键/值对的配置文件。如何读取密钥并找到值并可能对其进行修改？
回答by Cascabel
A wild stab in the dark for modifying a single value:
暗中修改单个值的疯狂尝试：
sed -c -i "s/\($TARGET_KEY *= *\).*/$REPLACEMENT_VALUE/" $CONFIG_FILE
assuming that the target key and replacement value don't contain any special regex characters, and that your key-value separator is "=". Note, the -c option is system dependent and you may need to omit it for sed to execute.
假设目标键和替换值不包含任何特殊的正则表达式字符，并且您的键值分隔符是“=”。请注意，-c 选项取决于系统，您可能需要省略它才能执行 sed。
For other tips on how to do similar replacements (e.g., when the REPLACEMENT_VALUE has '/' characters in it), there are some great examples here.
有关如何进行类似替换的其他提示（例如，当 REPLACEMENT_VALUE 中包含 '/' 字符时），这里有一些很好的示例。
回答by Rudi Strydom
Hope this helps someone. I created a self contained script, which required config processing of sorts.
希望这可以帮助某人。我创建了一个自包含脚本，它需要各种配置处理。
#!/bin/bash
CONFIG="/tmp/test.cfg"
# Use this to set the new config value, needs 2 parameters.
# You could check that and is set, but I am lazy
function set_config(){
sudo sed -i "s/^\(\s*=\s*\).*$//" $CONFIG
}
# INITIALIZE CONFIG IF IT'S MISSING
if [ ! -e "${CONFIG}" ] ; then
# Set default variable value
sudo touch $CONFIG
echo "myname=\"Test\"" | sudo tee --append $CONFIG
fi
# LOAD THE CONFIG FILE
source $CONFIG
echo "${myname}" # SHOULD OUTPUT DEFAULT (test) ON FIRST RUN
myname="Erl"
echo "${myname}" # SHOULD OUTPUT Erl
set_config myname $myname # SETS THE NEW VALUE
回答by vladr
Assuming that you have a file of key=valuepairs, potentially with spaces around the =, you can delete, modify in-place or append key-value pairs at will using awkeven if the keys or values contain special regex sequences:
假设您有一个key=value成对文件，可能在 周围有空格=，awk即使键或值包含特殊的正则表达式序列，您也可以随意删除、就地修改或附加键值对：
# Using awk to delete, modify or append keys
# In case of an error the original configuration file is left intact
# Also leaves a timestamped backup copy (omit the cp -p if none is required)
CONFIG_FILE=file.conf
cp -p "$CONFIG_FILE" "$CONFIG_FILE.orig.`date \"+%Y%m%d_%H%M%S\"`" &&
awk -F '[ \t]*=[ \t]*' '=="keytodelete" { next } =="keytomodify" { print "keytomodify=newvalue" ; next } { print } END { print "keytoappend=value" }' "$CONFIG_FILE" >"$CONFIG_FILE~" &&
mv "$CONFIG_FILE~" "$CONFIG_FILE" ||
echo "an error has occurred (permissions? disk space?)"
回答by ghostdog74
sed "/^$old/s/\(.[^=]*\)\([ \t]*=[ \t]*\)\(.[^=]*\)/$replace/" configfile
回答by tempcke
So I can not take any credit for this as it is a combination of stackoverflow answers and help from irc.freenode.net #bash channel but here are bash functions now to both set and read config file values:
所以我不能相信这一点，因为它是 stackoverflow 答案和来自 irc.freenode.net #bash 频道的帮助的组合，但现在这里有 bash 函数来设置和读取配置文件值：
# https://stackoverflow.com/a/2464883
# Usage: config_set filename key value
function config_set() {
local file=
local key=
local val=${@:3}
ensureConfigFileExists "${file}"
# create key if not exists
if ! grep -q "^${key}=" ${file}; then
# insert a newline just in case the file does not end with one
printf "\n${key}=" >> ${file}
fi
chc "$file" "$key" "$val"
}
function ensureConfigFileExists() {
if [ ! -e "" ] ; then
if [ -e ".example" ]; then
cp ".example" "";
else
touch ""
fi
fi
}
# thanks to ixz in #bash on irc.freenode.net
function chc() { gawk -v OFS== -v FS== -e 'BEGIN { ARGC = 1 } == ARGV[2] { print ARGV[4] ? ARGV[4] : , ARGV[3]; next } 1' "$@" <"" >".1"; mv ""{.1,}; }
# https://unix.stackexchange.com/a/331965/312709
# Usage: local myvar="$(config_get myvar)"
function config_get() {
val="$(config_read_file ${CONFIG_FILE} "")";
if [ "${val}" = "__UNDEFINED__" ]; then
val="$(config_read_file ${CONFIG_FILE}.example "")";
fi
printf -- "%s" "${val}";
}
function config_read_file() {
(grep -E "^=" -m 1 "" 2>/dev/null || echo "VAR=__UNDEFINED__") | head -n 1 | cut -d '=' -f 2-;
}
at first I was using the accepted answer's sed solution: https://stackoverflow.com/a/2464883/2683059
起初我使用的是公认答案的 sed 解决方案：https: //stackoverflow.com/a/2464883/2683059
however if the value has a / char it breaks
但是，如果该值有一个 / char 它会中断
回答by tempcke
in general it's easy to extract the info with grep and cut:
一般来说，使用 grep 和 cut 很容易提取信息：
cat "$FILE" | grep "^${KEY}${DELIMITER}" | cut -f2- -d"$DELIMITER"
to update you could do something like this:
要更新，您可以执行以下操作：
mv "$FILE" "$FILE.bak"
cat "$FILE.bak" | grep -v "^${KEY}${DELIMITER}" > "$FILE"
echo "${KEY}${DELIMITER}${NEWVALUE}" >> "$FILE"
this would not maintain the order of the key-value pairs obviously. add error checking to make sure you don't lose your data.
这显然不会保持键值对的顺序。添加错误检查以确保您不会丢失数据。
回答by datasunny
Suppose your config file is in below format:
假设您的配置文件采用以下格式：
CONFIG_NUM=4
CONFIG_NUM2=5
CONFIG_DEBUG=n
In your bash script, you can use:
在您的 bash 脚本中，您可以使用：
CONFIG_FILE=your_config_file
. $CONFIG_FILE
if [ $CONFIG_DEBUG == "y" ]; then
......
else
......
fi
$CONFIG_NUM, $CONFIG_NUM2, $CONFIG_DEBUGis what you need.
$CONFIG_NUM, $CONFIG_NUM2,$CONFIG_DEBUG正是您所需要的。
After your read the values, write it back will be easy:
读取值后，将其写回将很容易：
echo "CONFIG_DEBUG=y" >> $CONFIG_FILE
