I. Overview
1, the desktop environment:
Windows7, OpenSUSE 13.2, Kubuntu (KDE)
2, yum install Review
a, yum Package Manager
C/S：
yum client（yum）
yum repository（ftp/http/https）
base: the main package
extras: additional bag
updates: Upgrade Package
repo definitions
[id]
name=
baseurl=http://
http://
b, sub-command
list，clean，makecache，grouplist，whatprovides
install，update，remove，groupinstall，groupupdate，groupremove，groupinfo
yum install /usr/local/src/testapp-3.3.1-1.el7.x86_64.rpm # rpm package install this manner, when the install package relies rpm for other packages, if present, his warehouse yum resolve dependencies automatically install the appropriate dependencies. However, if you install the rpm package rpm -ivh by then it will not be resolved automatically.
3, compile and install Review
a、C/C++：
./configure --> Makefile.in ==> makefile
make + makefile ==> binary，library，configfile，manual
make install
Two, bash scripting
1, procedural programming language implementation process
Order execution
Choose Execute
Cycle execution
2, choose to perform:
（1）、&&，||
(2), if the statement
(3), case statements
3, if the statement: three formats -
a, a single branch of the if statement
if CONDITION；then
if-true- branch
be
b, two-branch if statement
if CONDITIOON；then
if-true- branch
else
if-false- branch
be
c, multi-branch if statement
if CONDITION1;then
A branch condition is true
elif CONDITION2;then
2 branch condition is true
elif CONDITION3;then
Condition 3 is true branch
...
elif CONDITIONn;then
N branch condition is true
else
Branch when all the conditions are not satisfied
be
Note: Even if a number of conditions may also be able to meet, the branch will only execute one of the first test is "true."
Example: a script parameters passed to the script file path, the file type is determined.
[root@localhost script]# cat filetype.sh #!/bin/bash if [ $# -lt 1 ];then echo "At least one path" exit 1 fi if ! [ -e "$1" ];then echo "No such file" exit 2 fi IF [-f $ . 1 ]; the then echo " the Common File " elif [-d $ . 1 ]; the then echo " Directory " elif [-L $ . 1 ]; the then # is a symbolic link is present and echo " Symbolic Link " elif [ $ -b 1 ]; the then echo " Block Special File " elif [-c $ 1 ]; the then echo " Character Special File " elif [$ -S1 ];then echo "Socket file" else echo "Unkown" fi [root@localhost script]# bash -n filetype.sh [root@localhost script]# bash -x filetype.sh /etc/ + '[' 1 -lt 1 ']' + '[' -e /etc/ ']' + '[' -f /etc/ ']' + '[' -d /etc/ ']' + echo Directory Directory
d, Note: if statement nestable
e, exercise: write a script
(1), passing a parameter to the script, this parameter is the user name
(2), according to its ID number to determine the type of user
0: Administrator
1-999: User
1000+: login
[root@localhost script]# cat usertype.sh #!/bin/bash [ $# -lt 1 ] && echo "At least on user name." && exit 1 ! id $1 &> /dev/null && echo "No such user." && exit 2 userid = $ ( a $ u 1 ) if [ $userid -eq 0 ];then echo "root" elif [ $userid -ge 1000 ];then echo "login user." else echo "System user." fi [root@localhost script]# bash -n usertype.sh [root@localhost script]# bash -x usertype.sh + '[' 0 -lt 1 ']' + echo 'At least on user name.' At least on user name. + exit 1 [root@localhost script]# bash -x usertype.sh root + '[' 1 -lt 1 ']' + id root ++ id -u root + userid=0 + '[' 0 -eq 0 ']' + echo root root
f, exercise: write a script
(1), a menu to the user as listed below
disk）show disks info
mem） show memory info
cpu） show cpu info
cat / proc / cpuinfo or can be ordered lscpu
*) quit
(2), prompt the user for their own choice, then the system displays the corresponding information selected corresponding to its
[root@localhost script]# cat sysinfo.sh #!/bin/bash cat <<EOF disk) show disks info mem) show memory info cpu) show cpu info *) QUIT EOF read -p "Your choice: " option if [[ "$option" == "disk" ]];then fdisk -l /dev/[sh]d[a-z] elif [[ "$option" == "mem" ]];then free -m elif [[ "$option" == "cpu" ]];then lscpu else echo "Unkown option." exit3 fi [root@localhost script]# bash sysinfo.sh disk) show disks info mem) show memory info cpu) show cpu info *) QUIT Your choice: mem total used free shared buff/cache available Mem: 1991 145 1031 9 815 1606 Swap: 2047 0 2047 [root@localhost script]#
Third, the cycle execution
1, the piece of code or 0,1 repeatedly performed a plurality of times
Entry conditions: when the conditions are met to enter circulation
Exit conditions: each cycle should have exit conditions to have the opportunity to exit the loop;
2, bash script in three ways
for loop
while loop
until loop
3, for circulation
a, two formats
(1), traverse the list
Generate a list of ways:
1) given directly
2), a list of integers
i、{start..end}
ii、seq
seq [OPTION] ... LAST: seq 3 will represent such three outputs 1,2,3 Number
seq [OPTION] ... FIRST LAST: seq 1 5 such as outputs 1 through says. 5
SEQ [the OPTION] ... FIRST LAST the INCREMENT: seq 1 2 11 example it means 1 to 11 in steps of 2 outputs, that is, each plus 2 output
[root@localhost script]# seq 1 2 11 1 3 5 7 9 11
3) returns a list of commands, such as ls / var or cat / etc / issue, etc., corresponding to the return value is a list of
4), glob, such as ls / etc / p *
5), variable references
$@，$*
(2), the control variable
b, traverse the list
for VARAIBLE in LIST;do
Loop
done
Entry conditions: As long as the list of available elements, you can enter the circulation.
Exit condition: the list of elements to traverse completed.
Example 1: Add users in bulk
[root@localhost script]# cat useradd3.sh #!/bin/bash for username in user21 user22 user23;do useradd $username done [root@localhost script]# bash -x useradd3.sh + for username in user21 user22 user23 + useradd user21 + for username in user21 user22 user23 + useradd user22 + for username in user21 user22 user23 + useradd user23 [root@localhost script]#
[root@localhost script]# cat useradd3.sh #!/bin/bash for username in user21 user22 user23;do if id $username &> /dev/null;then echo "$username exists." else useradd $username && echo "Add user $username finished." fi done
Example 2: Add 10 temporary file in / tmp
[root@localhost script]# cat addfile.sh #!/bin/bash for filename in $(seq 1 10);do touch /tmp/f$filename done [root@localhost script]# bash -x addfile.sh ++ seq 1 10 + for filename in '$(seq 1 10)' + touch /tmp/f1 + for filename in '$(seq 1 10)' + touch /tmp/f2 + for filename in '$(seq 1 10)' + touch /tmp/f3 + for filename in '$(seq 1 10)' + touch /tmp/f4 + for filename in '$(seq 1 10)' + touch /tmp/f5 + for filename in '$(seq 1 10)' + touch /tmp/f6 + for filename in '$(seq 1 10)' + touch /tmp/f7 + for filename in '$(seq 1 10)' + touch /tmp/f8 + for filename in '$(seq 1 10)' + touch /tmp/f9 + for filename in '$(seq 1 10)' + touch /tmp/f10
Example 3: Find all positive integers less than 100 and
[root@localhost script]# cat sum2.sh #!/bin/bash declare -i sum=0 for i in {1..100};do sum=$[ $sum+$i ] done echo $sum [root@localhost script]# bash sum2.sh 5050
A content type for each file in the judgment / var / log: Example 4
[root@localhost script]# cat filetype2.sh #!/bin/bash for filename in /var/log/*;do if [ -f $filename ];then echo "Common file" elif [ -d $filename ];then echo "Directory" elif [-L $ filename]; then # is a symbolic link exists and echo "Symbolic link" elif [-b $filename ];then echo "block special file" elif [ -c $filename ];then echo "character special file" elif [ -S $filename ];then echo "Socket file" else echo "Unkown" be done
Fourth, practice
1, respectively, all even find the sum of less than 100, and the sum of all odd
2, all calculated on the user id of the current system and
3, passed through a directory script parameters to the script, and then calculate the sum of all the text files in this directory and lines, and shows the total number of such files