This tutorial explains Linux “pwconv” command, options and its usage with examples. pwconv – convert to shadow passwords Description : The pwconv command creates shadow from passwd and an optionally existing shadow. pwconv and grpconv are similiar. First, entries in the shadowed file which don’t exist in the main file are removed. Then, shadowed entries … Read more
This tutorial explains Linux “pwck” command, options and its usage with examples. pwck – verify integrity of password files Description : pwck verifies the integrity of the system authentication information. All entries in the /etc/passwd and /etc/shadow are checked to see that the entry has the proper format and valid data in each field. The … Read more
This tutorial explains Linux “lastlog” command, options and its usage with examples. lastlog – examine lastlog file Description : lastlog formats and prints the contents of the last login log /var/log/lastlog file . The login-name, port, and last login time will be printed. The default (no flags) causes lastlog entries to be printed, sorted by … Read more
This tutorial explains Linux “grpconv” command, options and its usage with examples. grpconv – convert to shadow groups Description : The grpconv command creates gshadow from group and an optionally existing gshadow. Each program acquires the necessary locks before conversion. pwconv and grpconv are similar. First, entries in the shadowed file which don’t exist in … Read more
This tutorial explains Linux “grpck” command, options and its usage with examples. grpck – verify integrity of group files Description : The grpck command verifies the correctness of the group definitions in the user database files by checking the definitions for all the groups or for the groups that are specified by the Group parameter. … Read more
This tutorial explains Linux “newusers” command, options and its usage with examples. newusers – update and create new users in batch Description : newusers reads a file of user name and cleartext password pairs and uses this information to update a group of existing users or to create new users. Each line is in the … Read more
This tutorial explains Linux “tr” command, options and its usage with examples. tr – translate Description : The tr command is for translating, or deleting, or squeezing repeated characters. It will read from STDIN and write to STDOUT. Usage : tr [-Ccsu] string1 string2 In this form, the characters in the string string1 are translated … Read more
The uniq command in Linux eliminates duplicate lines from a file. It prints only the unique lines from a sorted file, preserving only one of a sequence of matching lines. Optionally, it can display only lines that appear exactly once or lines that appear multiple times. Syntax: The basic syntax of the uniq command in … Read more
This tutorial explains Linux “sort” command, options and its usage with examples. sort – Sorts the lines in a text file. Description : Write sorted concatenation of all FILE(s) to standard output. Usage : sort [OPTION]… [FILE]… Options : Ordering options: -b, –ignore-leading-blanks ignore leading blanks -d, –dictionary-order consider only blanks and alphanumeric characters -f, … Read more
This tutorial explains Linux “join” command, options and its usage with examples. join- Joins the data fields of two files. Description : The join command reads the files specified by the File1 and File2 parameters, joins lines in the files according to the flags, and writes the results to standard output. The File1 and File2 … Read more
