It failed to convert markdown to pdf file by pondoc on my CentOS8 server.I installed all missing components about texlive. But pandoc could’t find Chinese characters to generate complete PDF file. So I downloaded Chinese font file and install it.You can find source file on some font website such as https://chinesefonts.org/.Put Read more…
In DOS/Windows text files a line break, also known as newline, is a combination of two characters: a Carriage Return (CR) followed by a Line Feed (LF). In Unix text files a line break is a single character: the Line Feed (LF).You can use cat -A fileName to check if there is ^M$ in Read more…
Rename Files’ Suffixes Recursively And Find Folders Find Folders To find all folders in the current path, I wrote a simple shell script file. It ignores invisible folder which path looks like ./.XXX. #! /usr/bin/bash dirs=() find . -type d -print0 >tmpfile while IFS= read -r -d $’\0′; do dirs+=(“$REPLY”) Read more…
The following shell script is used to rename the files suffix at the current directory. After giving it the executable permission, we can use it like Code snippet: Result:
I want to write a bash script to listen for CPU resource usage. If there is a long time for high CPU consumption, the script will kill the relevant process. I refer to the qustion https://unix.stackexchange.com/questions/66786/bash-script-that-automatically-kills-processes-when-cpu-memory-usage-gets-too-hi on the stackexchange.
Inspiration: the famous fork bomb in the Linux world.Fork bomb::(){:|:&};. It’s like a crazy binary tree that consumes the resources of the system constantly. Fork bomb has an impact size of . The script here can’t do that terrible damage. Keep the size , use curl to access the target Read more…
Here is a bash script helps you to rename files *.c.gz to new files *.c. Code snippet: #! /bin/bash cmd1=$(ls |grep c.gz) cmd2=$(ls |grep c.gz |sed ‘s/\.gz//g’) array1=() len1=0 for i in $cmd1; do array1[$len1]=$i len1=$(expr $len1 + 1) done array2=() len2=0 for i in $cmd2; do array2[$len2]=$i len2=$(expr $len2 Read more…
I always get the error code 127 from my web application. I didn’t figure it out because it’s successful to run the program in the shell environment. The core logic in the calling function is like the following code snippet.
notes ${} 和 $[] $[expression] can calculate easily. ${expression} can tell us the value of a element in array. eg val1=23 val2=24 echo $val1+$val2 echo $[$val1+$val2] #it is equal to `echo $(( $val1+$val2 )` [edemon@CentOS workspace]$ ./incalc.sh 23+24 47 assign values to array. array=(`echo {1..10}`) echo ${array[0]}” “${array[9]} [edemon@CentOS workspace]$ Read more…