之前我们如果用一个命令，但是忘了具体的参数是什么的时候，通常会用man，比如
man tar
但是man有时候特别的冗长，你要找到想要的例子非常困难，所以tldr命令就是一个很好的补充，里边会有经常用到的例子和用法。
安装特别简单：
sudo curl -o /usr/local/bin/tldr https://raw.githubusercontent.com/raylee/tldr/master/tldr && sudo chmod +x /usr/local/bin/tldr
tldr tar
Archiving utility.
Often combined with a compression method, such as gzip or bzip.
- Create an archive from files:
tar cf target.tar file1 file2 file3
- Create a gzipped archive:
tar czf target.tar.gz file1 file2 file3
- Extract an archive in a target folder:
tar xf source.tar -C folder
- Extract a gzipped archive in the current directory:
tar xzf source.tar.gz
- Extract a bzipped archive in the current directory:
tar xjf source.tar.bz2
- Create a compressed archive, using archive suffix to determine the compression program:
tar caf target.tar.xz file1 file2 file3
- List the contents of a tar file:
tar tvf source.tar
- Extract files matching a pattern:
tar xf source.tar --wildcards "*.html"
tldr awk
A versatile programming language for working on files.
- Print the fifth column (a.k.a. field) in a space-separated file:
awk '{print $5}' filename
- Print the second column of the lines containing "something" in a space-separated file:
awk '/something/ {print $2}' filename
- Print the last column of each line in a file, using a comma (instead of space) as a field separator:
awk -F ',' '{print $NF}' filename
- Sum the values in the first column of a file and print the total:
awk '{s+=$1} END {print s}' filename
- Sum the values in the first column and pretty-print the values and then the total:
awk '{s+=$1; print $1} END {print "--------"; print s}' filename
tldr sed
Run replacements based on regular expressions.
- Replace the first occurrence of a string in a file, and print the result:
sed 's/find/replace/' filename
- Replace all occurrences of an extended regular expression in a file:
sed -E 's/regex/replace/g' filename
- Replace all occurrences of a string in a file, overwriting the file (i.e. in-place):
sed -i '' 's/find/replace/g' filename
- Replace only on lines matching the line pattern:
sed '/line_pattern/s/find/replace/' filename
- Apply multiple find-replace expressions to a file:
sed -e 's/find/replace/' -e 's/find/replace/' filename
- Replace separator / by any other character not used in the find or replace patterns, e.g., #:
sed 's#find#replace#' filename
原文:http://blog.csdn.net/hongchangfirst/article/details/79092945
作者:hongchangfirst
hongchangfirst的主页:http://blog.csdn.net/hongchangfirst
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作者：白杨树
来源：CSDN
原文：https://blog.csdn.net/hongchangfirst/article/details/79092945
