为啥报 readonly variable

338378WN8

写了一个脚本，用于将一台服务器上的USER信息复制到另一台上的。（一个suse，一个rhel）

while read USER UID GID DIR SH PASSWD
do
useradd -m -d $DIR -u $UID -g $GID -s $SH $USER
echo -e "$PASSWD\n$PASSWD\n" |passwd $USER
done < ftp_userpassword.txt

more [root@lxbftp01 ~]# more ftp_userpassword.txt
user1 1001    100     /ftp/user1   /bin/bash       passwd1
user2   1002    100     /ftp/user2       /bin/bash       passwd2
user3   1003    100     /ftp/user3      /bin/bash       passwd3


结果却是一直报错
./add_ftpuser.sh
./add_ftpuser.sh: line 5: UID: readonly variable
useradd: UID 0 is not unique
passwd: Unknown user name 'user1'.
./add_ftpuser.sh: line 5: UID: readonly variable
useradd: UID 0 is not unique
passwd: Unknown user name 'user2'.
./add_ftpuser.sh: line 5: UID: readonly variable
useradd: UID 0 is not unique
passwd: Unknown user name 'user3'.

奇怪的是，UID和GID都是数字，但是一个报错，一个正常，用bash -x 方式执行，可以看到gid都被正常赋值
+ read USER UID GID DIR SH PASSWD
add_ftpuser.sh: line 5: UID: readonly variable
+ useradd -m -d /ftp/user1 -u 0 -g 100 -s /bin/bash user1
useradd: UID 0 is not unique

请高手指点

nbrr

看abs, bash internal variables
http://tldp.org/LDP/abs/html/internalvariables.html
This is the current user's real id, even if she has temporarily assumed another identity through su. $UID is a readonly variable, not subject to change from the command line or within a script,

你可以换个名字
while read ftpUSER ftpUID ftpGID ftpDIR ftpSH ftpPASSWD

338378WN8

nbrr 发表于 2013-05-06 14:22
看abs, bash internal variables
http://tldp.org/LDP/abs/html/internalvariables.html
This is the cur ...

原来是和原有的变量重名了，多谢