shell 编程之2>&1_一树寒梅白玉条，迥临村路傍溪桥

shell 编程之2>&1_一树寒梅白玉条，迥临村路傍溪桥: "下面通过一个例子来展示2>&1有什么作用：
$ cat test.sh
t
date

test.sh中包含两个命令，其中t是一个不存在的命令，执行会报错，默认情况下，错误会输出到stderr。date则能正确执行，并且输出时间信息，默认输出到stdout
./test.sh > test1.log
./test.sh: line 1: t: command not found

$ cat test1.log
Tue Oct 9 20:51:50 CST 2007

可以看到，date的执行结果被重定向到log文件中了，而t无法执行的错误则只打印在屏幕上。
$ ./test.sh > test2.log 2>&1

$ cat test2.log
./test.sh: line 1: t: command not found
Tue Oct 9 20:53:44 CST 2007

这次，stderr和stdout的内容都被重定向到log文件中了。"

关于>&2、2>&1等重定向的详细解释_Road to OU (Oracle&Unix)

关于>&2、2>&1等重定向的详细解释_Road to OU (Oracle&Unix)

* 2>&1 就是将 stderr 并进 stdout 作输出
* 1>&2 或 >&2 就是将 stdout 并进 stderr 作输出

2.4 Special Keys

2.4 Special Keys: "Chapter 2: Getting Started on a UNIX System
2.4 Special Keys

Like all systems, UNIX has a number"

Name	Control Char	Function
erase	DEL or backspace	Erase character. Backspace and erase one character (the key used depends on terminal setting). Sometimes, especially within tcl/tk applications, you must use .
werase		Delete the rightmost word typed in.
kill		Kill (erase) the line typed in so far.[8]
intr		Interrupt the program currently running.
rprnt		Reprint the line typed in so far.
flush		Stops terminal output until you press a key.
susp		Suspend the program currently running and put it in the background. This does not stop the process as it does in VMS!
stop		Stop the display. To resume, press the start key
start		Start the display after stop.
eof		Send the program an end-of-file character.

Linux 一句话精彩问答基础知识 - Linux Unix As400

Linux 一句话精彩问答基础知识 - Linux Unix As400: "在有scsi硬盘的计算机上，如果用上面的命令挂载usb闪存，则会mount到/boot分区。这种情
况，应该先用fdisk -l /dev/sd? 来看看到底usb闪存盘是在哪个设备下(通常会是sdb或者sdc)。
比如某台机器上，就是在sdc1 上面。
所有/etc/fstab 内容 mount -a 指定文件格式'-t 格式', 格式可以为vfat, ext2, ext3 等.
访问DVD mount -t iso9660 /dev/dvd /mnt/cdrom 或mount -t udf /dev/dvd /mnt/cdrom
注意：dvd 的格式一般为iso9660 或udf 之一
1006 在vmware 的LINUX 中使用本地硬盘的FAT 分区
将本地的FAT 分区共享，然后在VMWARE 中使用SMBFS 挂上。可以将如下的行放到
/etc/fstab 中："

homework #1 set environment

-bash-3.00$ vi homework-1
CS385 Homework Assignment 1a
Subject: customize shell environment start up configuration file(s)
Due Date: Mar. 4, 2008

A. Study and understand each entry in the ".cshrc" and ".tcshrc" (if applicable) under your UNIX home directory on NPU's Sun workstation systems
B. COPY /cs385/.cshrc.base as your template and refer sample files ".cshrc.sample" and ".tcshrc.sample" under /cs385 on NPU48 (ONLY on NPU48!)
C. Polish your VI editing skill, make sure you are comfortable with cursor movement and vi commands
D. Create a duplicate of your current ".cshrc" file; Open 2nd connection to NPU48; edit ".cshrc" with VI:
i. Clean up unwanted and obsoleted entries such as lpath, extra aliases and comment-out lines
ii. Correct environment variables as appropriate, in particular, PATH, MANPATH, most importatnt function keys such as ERASE, INTERRUPT, STOP, SUSPEND, EOF and KILL; creat your favoriate aliases; add variable such as tabs, umask, filec, tty, noclobber, and history et al. set your prompt so it will display (minimum the following) your login-name, hostname (system name) and current working directory.
iii. Save your changes; execute command "source ~/.cshrc" or equivalent(.) in other shell to configure the file
iv. if no error after execution, you are ok; otherwise, repeate steps i through iii until no error
v. customize your .bash_profile in a way similar to above for .cshrc
E. Turn in a hard copy of your customzied ".cshrc" and ".bash_profile" file plus a soft copy to NPU48:/cs385/hmwk/hmwk-1 with a unique name such as "your-unix-login-name.cshrc" and "your-unix-login-name.bash_profile"

F. These who copy AND allow-others-to-copy their homework will get NULL for sure.

======Optional Bonus Questions ======
locate the ssh program embeded finger-print file for security keies on your Windows desktop


when finish:
1.soft.copy-> npu48: /cs385/hmwk/hmwk-1 with unique name.
2.hand.copy-> TA.


1..cshrc npu3 .33 for try csh






[npu3:/home/hanyunfan] cat .cshrc |more
# @(#)Cshrc 1.6 03/03/08 Frank
#################################################################
#
# .cshrc file
#
# For homework of cs385
# C-Shells
#
#################################################################

# Set Core Dump Size
limit coredumpsize 0k

set path = (~ $lpath ~/bin /usr/local/bin /usr/local/netscape /usr/ucb /usr/bin /usr/etc)
setenv MANPATH (/usr/man /usr/local/man)
setenv TERM=vt100
stty erase '^H' kill '^U' intr '^C' eof '^D' stop '^S' suspend '^z'

alias cd 'cd \!*;echo $cwd'
alias cp 'cp -i'
alias mv 'mv -i'
alias rm 'rm -i'
alias pwd 'echo $cwd'
alias h 'history \!* | head -39 | more'
alias dir 'ls'
alias pdw 'echo $cwd'
alias la 'ls -a'
alias ls 'ls -GF'

set ignoreeof # in case of ctrl+d
set noclobber # do not rewite exist file
set history=100
set savehist=40
set filec
set autolist
#set prompt="$USER@'hostname',<$cwd>:"
set prompt="%n%u@%m %~:"
umask 022









#.bash_profile
# Set Core Dump Size
limit coredumpsize 0k

export PATH =~:$lpath:~/bin:/usr/local/bin:/usr/local/netscape:/usr/ucb:/usr/bin:/usr/etc
export MANPATH /usr/man:/usr/local/man
set TERM=vt100;exprot TERM
export EDITOR=vi
stty erase '^H' kill '^U' intr '^C' eof '^D' stop '^S' suspend '^z'

alias cd 'cd \!*;echo $cwd'
alias cp 'cp -i'
alias mv 'mv -i'
alias rm 'rm -i'
alias pwd 'echo $cwd'
alias h 'history \!* | head -39 | more'
alias dir 'ls'
alias pdw 'echo $cwd'
alias la 'ls -a'
alias ls 'ls -GF'

set ignoreeof # in case of ctrl+d
set noclobber # do not rewite exist file
set history=100
set savehist=40
set filec
set autolist
export PS1="[\u@\h \W]\$"
umask 022

我的.cshrc文件

我的.cshrc文件: "# $FreeBSD: src/etc/root/dot.cshrc,v 1.29 2004/04/01 19:28:00 krion Exp $

#

# .cshrc - csh resource script, read at beginning of execution by each shell

#

# see also csh(1), environ(7).

lias h history 25

alias j jobs -l

alias la ls -a

alias lf ls -FA

alias ll ls -lA

alias lls ls -G

# A righteous umask

umask 22

set path = (/sbin /bin /usr/sbin /usr/bin /usr/games /usr/local/sbin /usr/local/bin /usr/X11R6/bin /usr/local/jdk1.4.2/bin /usr/local/jdk1.4.2/jre/bin $HOME/bin)

setenv EDITOR ee

setenv PAGER more

setenv BLOCKSIZE K

setenv LANG zh_CN.eucCN

setenv LC_ALL zh_CN.eucCN

setenv LC_CTYPE zh_CN.eucCN

setenv JAVA_HOME /usr/local/jdk1.4.2

setenv CLASSPATH .:$JAVA_HOME/lib:$JAVA_HOME/jre/lib:$JAVA_HOME/jre

setenv XMODIFIERS @im=fcitx

if ($?prompt) then

# An interactive shell -- set some stuff up

set prompt = '%B%m@%n[%/]# '

set filec

set history = 100

set savehist = 100

set mail = (/var/mail/$USER)

if ( $?tcsh ) then

bindkey '^W' backward-delete-word

bindkey -k up history-search-backward

bindkey -k down history-search-forward

endif

endif"

CSH Multiline prompt Linux on your way - Powered by Sablog-X

CSH Multiline prompt Linux on your way - Powered by Sablog-X: "# %B begin bold
# %b end bold
# %{ begin control escape
# %} end control escape, cannot be the last in prompt
# %m hostname, without domain
# %/ current directory
# %D day in dd format
# %W month in mm format
# %Y year in yyyy format
# %l tty
# %P time in 24 hour format
# %h history number"

tcshshell - pengpeng.popo - 网易博客

tcshshell - pengpeng.popo - 网易博客: "history -c"

history -c

关于Linux操作系统提示符PS1定义的问题-Linux伊甸园----Linux|Unix|新闻|下载|论坛|�

关于Linux操作系统提示符PS1定义的问题-Linux伊甸园----Linux|Unix|新闻|下载|论坛|�

Linux系统提示符是用系统变量PS1来定义的。一般系统默认的形式是：[username@host 工作目录]$.

用echo $PS1可以得到PS1的值，即PS1="[\u@\h \w]"\$

登录后可以更改PS1的显示样式，但是当退出重启登录进入系统后，样式又变成系统默认的样式了，如果要彻底改变它的样式，只能从配置文件中改。

PS是在用户根目录下的.bash_profile中定义的。

如

# .bash_profile

# Get the aliases and functions

if [ -f ~/.bashrc ]; then

. ~/.bashrc

fi

# User specific environment and startup programs

#以下是设定的PS1的值

PS1="[\u@\h \w]\$"

PATH=$PATH:$HOME/bin

#使用export把PS1输出，以使它可以在子shell中生效,这会造成ROOT用户的也采用此样式

#export PS1 要慎用

export PATH

unset USERNAME

下面简单说说环境下默认的特殊符号所代表的意义：

\d ：代表日期，格式为weekday month date，例如："Mon Aug 1"

\H ：完整的主机名称。例如：我的机器名称为：fc4.linux，则这个名称就是fc4.linux

\h ：仅取主机的第一个名字，如上例，则为fc4，.linux则被省略

\t ：显示时间为24小时格式，如：HH：MM：SS

\T ：显示时间为12小时格式

\A ：显示时间为24小时格式：HH：MM

\u ：当前用户的账号名称

\v ：BASH的版本信息

\w ：完整的工作目录名称。家目录会以 ~代替

\W ：利用basename取得工作目录名称，所以只会列出最后一个目录

\# ：下达的第几个命令

\$ ：提示字符，如果是root时，提示符为：# ，普通用户则为：$

（责任编辑：A6）

来源：赛迪网　供稿：sixth 　时间： 2007-11-07 13:43:06　评论0条　点击：阅读次数： 308次

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