md5sum

I have a situation where I have one VERY large file that I'm using the linux "split" command to break into smaller parts. Later I use the linux "cat" command to bring the parts all back together again. In the interim, however, I'm curious... If I get an MD5 fingerprint on the large file before splitting it, then later get the MD5 fingerprints on all the independent file parts that result from the split command, is there a way to take the independent fingerprints and somehow deduce that the sum or average (or whatever you like to all it) of their parts is equal to the fingerprint of the single

61.找文件差异 62.杀进程 63.并发备份数据库 64.监控CDN节点 65.破解字符串 66.判断cpu厂商 找文件差异 题目要求 有两个文件a.txt和b.txt，需求是，把a.txt中有的但b.txt中没有的行找出来，并写入到c.txt，然后计算c.txt文件的行数。 核心要求 可以使用while循环遍历a.txt,逐行进行匹配，如果这一行在b.txt中没有，就直接重定向到c.txt即可 grep -f 逐行匹配有的 ， grep -vf逐行查看没有的 grep -vf b.txt a.txt a中有的b中没有 代码 #!/bin/bash #这个脚本用来比较文件差异 cat a.txt|while read line do if ! grep -q "$line" b.txt then echo $line fi done >c.txt wc -l c.txt 杀进程 题目要求 把当前用户下所有进程名字中含有"aming"的进程关闭。 核心要点 ps -u $USER 代码 #!/bin/bash #这个脚本用来杀进程 ps -u $USER|awk '$NF ~ /aming/ {print $1}' |xargs kill 并发备份数据库 题目要求 用shell实现，以并发进程的形式将mysql数据库所有的表备份到当前目录，并把所有的表压缩到一个压缩包文件里。

I use md5sum to generate a hash value for a file. But i only need to receive the hash value, not the file name. md5=`md5sum ${my_iso_file}` echo ${md5} 3abb17b66815bc7946cefe727737d295 ./iso/somefile.iso How can i 'strip' the file name and only remain the value ? Well another way :) md5=`md5sum ${my_iso_file} | awk '{ print $1 }'` A simple array assignment works... Note that the first element of a bash array can be addressed by just the name without the [0] index, ie, $md5 contains only the 32 chars of the md5sum. md5=($(md5sum file)) echo $md5 # 53c8fdfcbb60cf8e1a1ee90601cc8fe2 Brian Campbell

I need to calculate a summary md5 checksum for all files of a particular type ( *.py for example) placed under a directory and all sub-directories. What is the best way to do that? Edit: The proposed solutions are very nice, but this is not exactly what I need. I'm looking for a solution to get a single summary checksum which will uniquely identify the directory as a whole - including content of all its sub-directories. find /path/to/dir/ -type f -name "*.py" -exec md5sum {} + | awk '{print $1}' | sort | md5sum The find command lists all the files that end in .py. The md5sum is computed for

I have made a code in python that checks for an md5 in a file and makes sure the md5 matches that of the original. Here is what I have developed: #Defines filename filename = "file.exe" #Gets MD5 from file def getmd5(filename): return m.hexdigest() md5 = dict() for fname in filename: md5[fname] = getmd5(fname) #If statement for alerting the user whether the checksum passed or failed if md5 == '>md5 will go here<': print("MD5 Checksum passed. You may now close this window") input ("press enter") else: print("MD5 Checksum failed. Incorrect MD5 in file 'filename'. Please download a new copy")