UNIX for Dummies Questions & Answers

hiii i have few questions..i hav just started using unix....i got two
doubts or problems as per now, if anyone can clarify it or solve it, his/her help is highly appreciated..
1) how to Rename all files which contain the sub-string 'foo', replacing it with 'bar' within a given folder.

2)How to Rename all the files within a folder with suffix “Unix_” i.e. suppose a folder has two files a.txt and b.pdf than they both should be renamed from a single command to Unix_a.txt and Unix_b.pdf

3)Suppose i have a C project in a folder called “project”, it contains .c and .h files, it also contains some other .txt files and .pdf files. So what is the command that will count the number of lines of my text files. That means total line count of every file. (i need to count the lines in .txt files only)

4)how to Rename all files within a folder with the first word of their content(all the files should be text files. For example if a.txt contains “Unix is an OS” in its first line then a.txt should be renamed to Unix.txt

and last but not the least is

5)how to use cut and sort command with history command


if u guys know answers to any of these questions your help is highly appreciated...

post in homework section
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