Commands by inof (7)

  • Some commands (such as sed and perl) have options to support in-place editing of files, but many commands do not. This shell function enables any command to change files in place. See the sample output for many examples. The function uses plain sh syntax and works with any POSIX shell or derivative, including zsh and bash. Show Sample Output


    1
    inplace() { eval F=\"\$$#\"; "$@" > "$F".new && mv -f "$F".new "$F"; }
    inof · 2010-04-09 11:36:31 8
  • Several people have submitted commands to do this, but I think this is the simplest solution. It also happens to be the most portable one: It should work with any sh or csh derived shell under any UNIX-like OS. Oh by the way, with my German locale ($LC_TIME set appropriately) it prints "g" most of the time, and sometimes (on Wednesdays) it prints "h". It never prints "y". Show Sample Output


    3
    date +%A | tail -2c
    inof · 2010-04-08 15:14:06 0
  • That one works on Linux. On BSD and Solaris, the ifconfig output is much easier to parse: /sbin/ifconfig -a | awk '/inet/{print $2}'


    0
    /sbin/ifconfig | awk -F'[ :]+' '/inet addr/{print $4}'
    inof · 2009-07-21 14:18:17 2
  • This is *NOT* about the -i option in grep. I guess everybody already knows that option. This is about the basic rule of life that the simplest things are sometimes the best. ;-) One day when I used "grep -i" for the umpteenth time, I decided to make this alias, and I've used it ever since, probably more often than plain grep. (In fact I also have aliases egrip and fgrip defined accordingly. I also have wrip="grep -wi" but I don't use this one that often.) If you vote this down because it's too trivial and simplistic, that's no problem. I understand that. But still this is really one of my most favourite aliases.


    -2
    alias grip="grep -i"
    inof · 2009-07-21 11:12:15 2
  • This alias finds identical lines in a file (or pipe) and prints a sorted count of them (the name "sucs" descends from the first letters of the commands). The first example shows the number of logins of users; the one who logged in most often comes last. The second example extracts web client IP addresses from a log file, then pipes the result through the "sucs" alias to find out which clients are performing the most accesses. Or pipe the first column of ps(1) output through "sucs" to see how many processes your users are running. Show Sample Output


    0
    alias sucs="sort | uniq -c | sort -n"
    inof · 2009-07-21 10:55:06 0
  • This shell snippet reads a single keypress from stdin and stores it in the $KEY variable. You do NOT have to press the enter key! The key is NOT echoed to stdout! This is useful for implementing simple text menus in scripts and similar things.


    5
    stty cbreak -echo; KEY=$(dd bs=1 count=1 2>/dev/null); stty -cbreak echo
    inof · 2009-06-09 13:15:49 4

  • 5
    awk '/match/{print NR}' file
    inof · 2009-06-03 17:34:13 3

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Quick case-insenstive partial filename search
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Ease your directory exploration
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force a rescan on a host of scsi devices (useful for adding partitions to vmware on the fly)

Lists all usernames in alphabetical order

Print out a man page
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Convert seconds to [DD:][HH:]MM:SS
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randomize hostname and mac address, force dhcp renew. (for anonymous networking)
this string of commands will release your dhcp address, change your mac address, generate a new random hostname and then get a new dhcp lease.

route output as next command's parameters

Tail a log file with long lines truncated
This truncates any lines longer than 80 characters. Also useful for looking at different parts of the line, e.g. cut -b 50-100 shows columns 50 through 100.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials


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