在 /etc/environment 中添加或更新配置记录

Question

我的/etc/environment看起来像这样：

cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"

我希望使用一个命令（sed、awk、python 等等……），让它看起来像这样：

cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
JAVA_HOME="/usr/lib/jvm/java-6-sun"

现在问题是，我宁愿它是 1 行（在 sed -XYZ /DoMagic/ /etc/environment 的字段中），它需要包含合并逻辑，即 - 附加新的配置记录或更新现有的. 最重要的是，它应该防止文件看起来像这样：（由有经验的 shell 脚本编写者在每次调用时调用 echo >> 引起）

cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
JAVA_HOME="/usr/lib/jvm/java-5-sun"
JAVA_HOME="/usr/lib/jvm/java-6-sun"
JAVA_HOME="/usr/lib/jvm/java-6-sun"
JAVA_HOME="/usr/lib/jvm/java-6-sun"

我想这是一个棘手的问题，因为我试图避免使用自定义脚本，例如

/usr/local/bin/PropUpdate /etc/environment JAVA_HOME "/usr/lib/jvm/java-6-sun"

---

/usr/local/bin/PropUpdate是以下脚本（为了示例而编写，可能包含错误。感谢评论）

#!/bin/bash

# Append/Update a configuration record in a file
#
# Usage example:
# /usr/local/bin/PropUpdate /etc/environment JAVA_HOME "/usr/lib/jvm/java-6-sun"
#
# Author Maxim Veksler <maxim@vekslers.org>
# Version 0.5-2010-07-27


EXPECTED_ARGS=3
E_BADARGS=3
E_BADFILE=4

if [[ $# -ne ${EXPECTED_ARGS} ]]; then
  echo "Usage: `basename $0` /path/to/config.conf ParameterName newValueText" >&2
  exit $E_BADARGS
fi

CONFIGURATION_FILE="$1"
CONFIGURATION_PARAMETER="$2"
CONFIGURATION_VALUE="$3"

if [[ ! -e "${CONFIGURATION_FILE}" ]]; then
        echo "Configuration file ${CONFIGURATION_FILE} does not exist" >&2
        exit $E_BADFILE
fi

if [[ ! -w "${CONFIGURATION_FILE}" ]]; then
        echo "Can't modify ${CONFIGURATION_FILE}" >&2
        exit $E_BADFILE
fi



#########################################
## Decide what parameter we are adding ##
#########################################
__param_found=0

# First check CONFIGURATION_PARAMETER supplied by use that contains "="
if [[ ${CONFIGURATION_PARAMETER} == *=* ]]; then
        # It should exist in the file, plain
        if grep -qE "^${CONFIGURATION_PARAMETER}" "${CONFIGURATION_FILE}"; then
                __param_found=1
                SUFFIX_REGEX='[[:space:]]*'
        fi
else
        # OK, sophisticated user, did not send "=" with the parameter...
        if grep -qE "^${CONFIGURATION_PARAMETER}[[:space:]]*=" "${CONFIGURATION_FILE}"; then
                # Let's check if such configuration with Parameter + "=" exists
                __param_found=1
                SUFFIX_REGEX='[[:space:]]*=[[:space:]]*'
        elif grep -qE "^${CONFIGURATION_PARAMETER}[[:space:]]+" "${CONFIGURATION_FILE}"; then
                # If such parameter exists, at all
                __param_found=1
                SUFFIX_REGEX='[[:space:]]\+'
        fi
fi


if [[ $__param_found == 1 ]]; then
        #echo sed -i "s|^\(${CONFIGURATION_PARAMETER}${SUFFIX_REGEX}\).*$|\1${CONFIGURATION_VALUE}|g" "${CONFIGURATION_FILE}"
        sed -i "s|^\(${CONFIGURATION_PARAMETER}${SUFFIX_REGEX}\).*$|\1${CONFIGURATION_VALUE}|g" "${CONFIGURATION_FILE}"

else
        if [[ ${CONFIGURATION_PARAMETER} == *=* ]]; then
                # Configuration parameter contains "=" in it's name, good just append
                echo "${CONFIGURATION_PARAMETER}${CONFIGURATION_VALUE}" >> "${CONFIGURATION_FILE}"
        else
                # Try to guess if this file is a "param = value" or "param value" type of file.
                if grep -qE "^[[:alnum:]]+[[:space:]]*=" "${CONFIGURATION_FILE}"; then
                        # Seems like a "param = value" type of file
                        echo "${CONFIGURATION_PARAMETER}=${CONFIGURATION_VALUE}" >> "${CONFIGURATION_FILE}"
                else
                        # Seems like a "param  value" type of file
                        echo "${CONFIGURATION_PARAMETER} ${CONFIGURATION_VALUE}" >> "${CONFIGURATION_FILE}"
                fi
        fi
fi

#cat $CONFIGURATION_FILE

谢谢你，马克西姆。

-- 更新：我其实有点喜欢这个脚本，所以我对它做了一些改进。现在似乎已经准备好生产了。享受。

Answer 1

/etc/environment您可以在 中创建一个具有您自己名称的文件，而不是尝试解析文件，正如我在对相关问题的回答/etc/profile.d/中所述。然后您可以在安装过程中复制它，因为它只包含您的内容。更不用说它会让你的脚本变得更短。