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Full Discussion: Speeding up shell script with grep
Top Forums Shell Programming and Scripting Speeding up shell script with grep Post 302994609 by Don Cragun on Saturday 25th of March 2017 06:07:42 AM
Old 03-25-2017
In addition to what bakunin suggested, you might also consider the following to more closely match the output produced by your current script...

Making the wild assumptions that:
  1. master.csv is a character separated values file with comma as the character separating fields, and
  2. the field containing the phone number in master.csv is the 1st field
how long does the following script take:
Code:
awk -v fn=1 -F',' '
FNR == NR {
	p[$fn]
	next
}
{	print "checking master for phone number", $1
	if($1 in p) {
		print $1, "already exists in master file "
		print > "unusable_numbers"
	} else {
		print $1, "looks good we can use this saving to usable_numbers"
		print > "useable_numbers"
	}
}' master.csv new

to do the same job?

If the field number in master.csv is not the 1st field, change the value assigned to the fn variable from 1 to the field number of the field containing the phone number.

If the field separators in master.csv are not commas, change the character in the -F option-argument to the desired character.
 

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LEARN ABOUT SUSE

chfn

chfn(1) 						      General Commands Manual							   chfn(1)

NAME

       chfn - change finger information

SYNOPSIS

       chfn [-D binddn] [-P path] [-f name] [-o office] [-p phone] [-h home_phone] [-m other] [-r service] [-q] [-u] [-v] [user]

DESCRIPTION

       chfn  is  used  to  change the user finger information. This are the users fullname, office room number, office phone number and home phone
       number. This information is stored in the /etc/passwd file and typically printed by finger(1) and similiar programs. A normal user may only
       change  the  fields  for  their own account, the super user may change the fields for any account. Also, only the super user may use the -o
       option to change the undefined portions of the GECOS field.

       If no information is given on the command line, chfn operates in an interactive fashion, prompting the user for each field.  Enter the  new
       value  to  change  the field, or leave the line blank to use the current value. Enter none or a blank only to remove the current value. The
       current value is displayed between a pair of [ ] marks.

       The only restrictions placed on the contents of the fields is that no control characters may be present, nor any of comma, colon, or  equal
       sign. The other field does not have this restriction, and is used to store accounting information used by other applications.

       This version of chfn is able to change the shell of local, NIS, NIS+ and LDAP accounts, if the permissions allow it.

OPTIONS

       -D, --binddn binddn
	      Use  the	Distinguished  Name binddn to bind to the LDAP directory.  The user will be prompted for a password for simple authentica-
	      tion.

       -P, --path path
	      The passwd and shadow files are located below the  specified  directory  path.  chfn  will  use  this  files,  not  /etc/passwd  and
	      /etc/shadow.   This  is  useful for example on NIS master servers, where you do not want to give all users in the NIS database auto-
	      matic access to your NIS server and the NIS map is build from special files.

       -f, --full-name
	      Specify your real name.

       -o, --office
	      Specify your office room number.

       -p, --phone
	      Specify your office phone number.

       -h, --home-phone
	      Specify your home phone number.

       -m, --other
	      Specify the undefined portions of the GECOS field.

       -r, --service
	      Specify the service where the GECOS field should be changed.  Supported services are files, ldap, nis and nisplus.

       -q, --quite
	      Don't be verbose.

       -u, --usage
	      Print a usage message and exit.

	   --help
	      Print a more verbose help text and exit.

       -v, --version
	      Print version information and exit.

ENVIRONMENT

       SHADOW_CHFN - If this environment variable is set to 1, the chfn options are compatible to the version from the shadow suite.

FILES

       /etc/passwd - user account information

SEE ALSO

       chsh(1), finger(1), passwd(5)

AUTHOR

       Thorsten Kukuk <kukuk@suse.de>

pwdutils							   February 2004							   chfn(1)
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