Lao Li share: "Linux shell Script Raiders" Essentials (iii)

1, the production of any size file [[email protected] dd_test]#
[[email protected] dd_test]# dd If=/dev/zero of=junk.data bs=1k count=10
10+0 Records in
10+0 Records out
10240 bytes (Ten kB) copied, 0.00137023 S, 7.5 mb/s 2, File system related test [-f $file _var]: The given variable contains a normal file path or file name, returns True [-D $var]: The given variable is the target True if the record is returned. [-e $var]: Returns True if the given variable contains a file that exists. [[-Z $STR 1]]: Returns True if Str1 contains an empty string. [[-N $str 1]]: Returns True if STR1 contains a non-empty string. -GT: Greater than-lt: less than-ge: greater than or equal to.-le: less than or equal to. 3, file permissions [[email protected] program_test]# chmod 777 cnts.sh 4, batch generated files of any size

[email protected] touch_more]# cat create_morefile.sh
#!/bin/bash
For name in {1..100}.txt
Do
Touch $name
DD If=/dev/zero of= $name bs=1k count=1
Done

5. Generate Symbolic link file [[email protected] touch_more]# ln-s 100.txt 100_symbol.txt
[Email protected] touch_more]# Ll-al 100*
lrwxrwxrwx. 1 root root 7 Jan 2 00:24 100_symbol.txt-100.txt
-rw-r--r--. 1 root root 2 00:22 100.txt Find symbolic Link file method one: [[email protected] touch_more]# Ls-al | grep ' ^l ' | awk ' {print $9} '//feature tag, starting with L.
100_symbol.txt method Two: [[email protected] touch_more]# find./-type L
./100_symbol.txt print Symbolic link to file name: [[email protected] touch_more]# Ls-al 100_symbol.txt | awk ' {print $11} '
100.txt 6, Traversal files, classification type statistics file

[email protected] touch_more]# cat filestat.sh

#!/bin/bash

If [$#-ne 1];

Then

echo $ basepath;

Exit 1

Fi

Path=$1

Declare-a Statarray;

while read line;

Do

ftype=$ (file-b "$line")

Let statarray["$ftype"]++;

Done < < (find $path-type f-print)//In child process statistics file name

echo ===================file types and counts ===============

For ftype in "${!statarray[@]}"; Array table

Do

echo $ftype: ${statarray["$ftype"}

Done

6, real-time viewing of the growing file [[email protected] touch_more]# tail-f filestat.sh 7, directory switching [[email protected] program_test]# CD-
/home/yxx/program_test/touch_more

Lao Li share: "Linux shell Script Raiders" Essentials (iii)