filestat

This application was an assignment for Operating System exam, part of L-31 Bachelor Degree (Information Technology) in University of Camerino in 2018

Description

Develop a Unix/Linux system application called filestat which is capable of monitoring a set of files collecting info about:

• size (byte);
• permissions;
• time of last access;
• time of last modification;
• time of last status change;
• number of links at file;
• owner;
• group.

Program synopsis is the following:
filestat [options] [input] [output] Where:

• input is the input file which contains executing arguments of program, if omitted is used filestat.in;
• output is the output file where collected data is stored, if omitted is used filestat.db. Informations contained into output file are updated at any program execution (and not overwrited);

Possible options are the following:

 --verbose | -v  
 --stat | -s  
 --report | -r  
 --history | -h <filepath>  
 --user | -u <userID>  
 --group | -g <groupID>   
 --length | -l <min>:<max>   
 --noscan  

Following are the options description:
- –verbose|-v: during program execution it print informations about elaborated files, and collected data;
- –stat|-s: the following stats are shown on standard output:
1. number of monitored files;
2. number of links;
3. number of directories;
4. total size;
5. average size;
6. maximum size;
7. minimum size (byte).
- –report|-r: at the end of execution are shown information about number of monitored files, time of execution, maximum size;
- –history|-h <filepah>: shows on standard output data history of file <filepah>;
- –user|-u <userId>: shows on standard output info of all files owned by <userId>;
- –group|-g <groupId>: shows on standard output info of all files owned by <groupId>;
- –length|-l <min>:<max>: shows on standard output info of all files that have size (byte) between<min> and <max> (:<max> stands for any file which is at maximum <max> in size, <min>: and <min> stands for any file which is at least <min> in size)

Input file format

Executing arguments are defined in a text file made of a sequences of row with the following format:
<path> [r] [l]
Where r indicates that is necessary read recursively files on subdirectories (applying same options) while l indicates that links must be treated as regular file/directory, in this case data collected refers to file reffered by the link and not link itself .

Output file format

Collected data is structured as following:

# <path1>  
<data1> <uid1> <gid1> <dim1> <perm1> <acc1> <change1> <mod1> <nlink1>  
…  
<data_n> <uid_n> <gid_n> <dim_n> <perm_n> <acc_n> <change_n> <mod_n> <nlink_n>  
###  
# <path2> 
<data1> <uid1> <gid1> <dim1> <perm1> <acc1> <change1> <mod1> <nlink1> 
…  
<data_n> <uid_n> <gid_n> <dim_n> <perm_n> <acc_n> <change_n> <mod_n> <nlink_n>  
###  
… # <pathm>  
<data1> <uid1> <gid1> <dim1> <perm1> <acc1> <change1> <mod1> <nlink1>  
…  
<data_n> <uid_n> <gid_n> <dim_n> <perm_n> <acc_n> <change_n> <mod_n> <nlink_n>   
###  
### 

Info associated at directory/file <path> begin with:
# <path>
Then there are a sequence of rows (one for every analyze done) with the following format:
<data> <uid> <gid> <dim> <perm> <acc> <change> <mod> <nlink>
Where:
- <data> indicates time of when info have been collected;
- <uid> is owner's user ID;
- <gid> is owner's group ID;
- <perm> is the permissions string;
- <acc> time of last access;
- <change> time of last modification
- <mod> time of last status change;
- <nlink> number of link forward to file.

Info end with the following row:
###
File ends with the following row:
###