{"id":21,"date":"2019-07-05T01:51:00","date_gmt":"2019-07-05T01:51:00","guid":{"rendered":"http:\/\/pro369.com\/linux\/?p=21"},"modified":"2019-07-05T01:51:00","modified_gmt":"2019-07-05T01:51:00","slug":"linux-%e7%b3%bb%e7%b5%b1%e7%ae%a1%e7%90%86%e7%af%87%ef%bc%88%e7%92%b0%e5%a2%83%e8%ae%8a%e9%87%8f%ef%bc%89","status":"publish","type":"post","link":"https:\/\/por.tw\/linux\/linux-%e7%b3%bb%e7%b5%b1%e7%ae%a1%e7%90%86%e7%af%87%ef%bc%88%e7%92%b0%e5%a2%83%e8%ae%8a%e9%87%8f%ef%bc%89\/","title":{"rendered":"Linux \u7cfb\u7d71\u7ba1\u7406\u7bc7\uff08\u74b0\u5883\u8b8a\u91cf\uff09"},"content":{"rendered":"

Linux \u7cfb\u7d71\u7ba1\u7406\u7bc7\uff08\u74b0\u5883\u8b8a\u91cf\uff09<\/p>\n

1. \u986f\u793a\u74b0\u5883\u8b8a\u91cfHOME
$ echo $HOME
\/home\/terry
2. \u8a2d\u5b9a\u4e00\u500b\u65b0\u7684\u74b0\u5883\u8b8a\u91cfWELCOME
$ export WELCOME="Hello!"
$ echo $WELCOME
Hello!
3. \u4f7f\u7528env\u6307\u4ee4\u986f\u793a\u6240\u6709\u7684\u74b0\u5883\u8b8a\u91cf
$ env
HOSTNAME=terry.mykms.org
PVM_RSH=\/usr\/bin\/rsh
SHELL=\/bin\/bash
TERM=xterm
HISTSIZE=1000
4. \u4f7f\u7528set\u6307\u4ee4\u986f\u793a\u6240\u6709\u672c\u5730\u5b9a\u7fa9\u7684Shell\u8b8a\u91cf
$ set
BASH=\/bin\/bash
BASH_VERSINFO=([0]="2"[1]="05b"[2]="0"[3]="1"[4]="release"[5]="i386-redhat-linux-gnu")
BASH_VERSION='2.05b.0(1)-release'
COLORS=\/etc\/DIR_COLORS.xterm
COLUMNS=80
DIRSTACK=()
DISPLAY=:0.0
5. \u4f7f\u7528unset\u6307\u4ee4\u4f86\u6e05\u9664\u74b0\u5883\u8b8a\u91cf
set\u53ef\u4ee5\u8a2d\u5b9a\u67d0\u500b\u74b0\u5883\u8b8a\u91cf\u7684\u503c\u3002\u6e05\u9664\u74b0\u5883\u8b8a\u91cf\u7684\u503c\u7528unset\u6307\u4ee4\u3002\u5982\u679c\u672a\u6307\u5b9a\u503c\uff0c\u5247\u8a72\u8b8a\u91cf\u503c\u5c07\u88ab\u8a2d\u70baNULL\u3002\u793a\u4f8b\u5982\u4e0b\uff1a
$ export TEST="Test…" #\u589e\u52a0\u4e00\u500b\u74b0\u5883\u8b8a\u91cfTEST
$ env|grep TEST #\u6b64\u6307\u4ee4\u6709\u8f38\u5165\uff0c\u8b49\u660e\u74b0\u5883\u8b8a\u91cfTEST\u5df2\u7d93\u5b58\u5728\u4e86
TEST=Test…
$ unset $TEST #\u522a\u9664\u74b0\u5883\u8b8a\u91cfTEST
$ env|grep TEST #\u6b64\u6307\u4ee4\u6c92\u6709\u8f38\u51fa\uff0c\u8b49\u660e\u74b0\u5883\u8b8a\u91cfTEST\u5df2\u7d93\u5b58\u5728\u4e86
6. \u4f7f\u7528readonly\u6307\u4ee4\u8a2d\u5b9a\u552f\u8b80\u8b8a\u91cf
\u5982\u679c\u4f7f\u7528\u4e86readonly\u6307\u4ee4\u7684\u8a71\uff0c\u8b8a\u91cf\u5c31\u4e0d\u53ef\u4ee5\u88ab\u4fee\u6539\u6216\u6e05\u9664\u4e86\u3002\u793a\u4f8b\u5982\u4e0b\uff1a
$ export TEST="Test…" #\u589e\u52a0\u4e00\u500b\u74b0\u5883\u8b8a\u91cfTEST
$ readonly TEST #\u5c07\u74b0\u5883\u8b8a\u91cfTEST\u8a2d\u70ba\u552f\u8b80
$ unset TEST #\u6703\u767c\u73fe\u6b64\u8b8a\u91cf\u4e0d\u80fd\u88ab\u522a\u9664
-bash: unset: TEST: cannot unset: readonly variable
$ TEST="New" #\u6703\u767c\u73fe\u6b64\u4e5f\u8b8a\u91cf\u4e0d\u80fd\u88ab\u4fee\u6539
-bash: TEST: readonly variable
7. \u7528C\u7a0b\u5f0f\u4f86\u8a2a\u554f\u548c\u8a2d\u5b9a\u74b0\u5883\u8b8a\u91cf
\u5c0d\u65bcC\u7a0b\u5f0f\u7684\u4f7f\u7528\u8005\u4f86\u8aaa\uff0c\u53ef\u4ee5\u4f7f\u7528\u4e0b\u5217\u4e09\u500b\u51fd\u6578\u4f86\u8a2d\u5b9a\u6216\u8a2a\u554f\u4e00\u500b\u74b0\u5883\u8b8a\u91cf\u3002
\u25c6 getenv()\u8a2a\u554f\u4e00\u500b\u74b0\u5883\u8b8a\u91cf\u3002\u8f38\u5165\u53c3\u6578\u662f\u9700\u8981\u8a2a\u554f\u7684\u8b8a\u91cf\u540d\u5b57\uff0c\u8fd4\u56de\u503c\u662f\u4e00\u500b\u5b57\u4e32\u3002\u5982\u679c\u6240\u8a2a\u554f\u7684\u74b0\u5883\u8b8a\u91cf\u4e0d\u5b58\u5728\uff0c\u5247\u6703\u8fd4\u56deNULL\u3002
\u25c6 setenv()\u5728\u7a0b\u5f0f\u88e1\u9762\u8a2d\u5b9a\u67d0\u500b\u74b0\u5883\u8b8a\u91cf\u7684\u51fd\u6578\u3002
\u25c6 unsetenv()\u6e05\u9664\u67d0\u500b\u7279\u5b9a\u7684\u74b0\u5883\u8b8a\u91cf\u7684\u51fd\u6578\u3002
\u53e6\u5916\uff0c\u9084\u6709\u4e00\u500b\u6307\u6a19\u8b8a\u91cfenviron\uff0c\u5b83\u6307\u5411\u7684\u662f\u5305\u62ec\u6240\u6709\u7684\u74b0\u5883\u8b8a\u91cf\u7684\u4e00\u500b\u6e05\u55ae\u3002\u4e0b\u9762\u7684\u7a0b\u5f0f\u53ef\u4ee5\u5217\u5370\u51fa\u73fe\u7528\u7684\u904b\u884c\u74b0\u5883\u88e1\u9762\u7684\u6240\u6709\u74b0\u5883\u8b8a\u91cf\uff1a
\uff03i nclude
extern char**environ;
int main ()
{
char**var;
for (var =environ;*var !=NULL;++var)
printf ("%s ",*var);
return 0;
}<\/p>\n

Linux\u4e0b\u7684\u74b0\u5883\u8b8a\u91cf\u8a2d\u5b9a
# \/etc\/profile
# System wide environment and startup programs, for login setup
# Functions and aliases go in \/etc\/bashrc
pathmunge () {
if ! echo $PATH | \/bin\/egrep -q "(^|:)$1($|:)" ; then
if [ "$2" = "after" ] ; then
PATH=$PATH:$1
else
PATH=$1:$PATH
fi
fi
}
# Path manipulation
if [ `id -u` = 0 ]; then
pathmunge \/sbin
pathmunge \/usr\/sbin
pathmunge \/usr\/local\/sbin
fi
pathmunge \/usr\/X11R6\/bin after
unset pathmunge
# No core files by default
ulimit -S -c 0 > \/dev\/null 2>&1
USER="`id -un`"
LOGNAME=$USER
MAIL="\/var\/spool\/mail\/$USER"
HOSTNAME=`\/bin\/hostname`
HISTSIZE=1000
if [ -z "$INPUTRC" -a ! -f "$HOME\/.inputrc" ]; then
INPUTRC=\/etc\/inputrc
fi
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUTRC
for i in \/etc\/profile.d\/*.sh ; do
if [ -r "$i" ]; then
. $i
fi
done
unset i
JAVA_HOME="\/opt\/j2sdk1.4.2_01"
MYSQL_HOME="\/var\/mysql"
CLASSPATH=.:$JAVA_HOME\/lib\/tools.jar:$JAVA_HOME\/lib\/dt.jar
PATH=$PATH:$JAVA_HOME\/bin:$MYSQL_HOME\/bin:\/opt\/apache-ant-1.5.4\/bin
export JAVA_HOME CLASSPATH PATH
CVSROOT=\/cvsroot;
export CVSROOT
LINUX\u7cfb\u7d71\u74b0\u5883\u8b8a\u91cf
\/etc\/profile\u5c0d\u6574\u500b\u7cfb\u7d71\u6709\u6548.
\u78ba\u5b9a\u4f60\u4f7f\u7528\u7684\u662fbash
\u4fee\u6539~\/.bash_profile
\u628a\u4f60\u8981\u8a2d\u5b9a\u7684\u74b0\u5883\u8b8a\u91cf\u5beb\u9032\u53bb
\u4f8b\u5982
JAVA_HOME=\/usr\/local\/jdk
export JAVA_HOME<\/p>\n","protected":false},"excerpt":{"rendered":"

Linux \u7cfb\u7d71\u7ba1\u7406\u7bc7\uff08\u74b0\u5883\u8b8a\u91cf\uff09 1. \u986f\u793a\u74b0\u5883\u8b8a\u91cfHOME $ echo $HOME \/home\/terr […]<\/p>\n","protected":false},"author":1,"featured_media":493,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[20],"class_list":["post-21","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-linux","tag-linux"],"_links":{"self":[{"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/posts\/21"}],"collection":[{"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/comments?post=21"}],"version-history":[{"count":0,"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/posts\/21\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/media\/493"}],"wp:attachment":[{"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/media?parent=21"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/categories?post=21"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/por.tw\/linux\/wp-json\/wp\/v2\/tags?post=21"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}