Sponsored Content
The Lounge What is on Your Mind? Quest for the most useless command Post 302882166 by radoulov on Saturday 4th of January 2014 06:20:07 PM
Old 01-04-2014
Quote:
Originally Posted by MadeInGermany
Code:
true

in shell can always be replaced by the built-in command
Code:
:

Note that in most shells true is a shell builtin as well:

Code:
[root ~]# for _sh in bash ksh mksh dash zsh; do 
  printf '%s: %s\n' "$_sh" "$("$_sh" -c 'type true')"
done 
bash: true is a shell builtin
ksh: true is a shell builtin
mksh: true is a shell builtin
dash: true is a shell builtin
zsh: true is a shell builtin

And it's definitely more readable than `:' Smilie
 

6 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

a quest regarding the path?

Hi mates, A newbe in UNIX world. how can i add a specific path to my default unix path. ie i want to add a directory let is say /abdul to the path and whenever i log in unix should recognize it. it is mostly importnant when i use the cc command to compile my c programs ...and i have to use ./cc... (2 Replies)
Discussion started by: abdul
2 Replies

2. UNIX for Dummies Questions & Answers

useless command

Hi, I came across with this line "set -x" in the beginning of a script, but i can't find one logic reason for this... should be something else after, i think.... anyone can help? tanx (2 Replies)
Discussion started by: cabresto
2 Replies

3. UNIX for Advanced & Expert Users

IBM Quest Market-Basket Synthetic Data Generator

Hi All, I am trying to install the IBM data set generator. I have to use the Solaris to use this tool. The following link is supposed to tell the steps on how to use the IBM tool on the Solaris server. IBM Quest Market-Basket Synthetic Data Generator Unfortunately, I don't understand what is... (2 Replies)
Discussion started by: loollool
2 Replies

4. UNIX for Advanced & Expert Users

Quest on NFS with 1 Server & 2 Clients

Hello; I work now with a team which has based her "applications" on the following schema: 1 NFS client C1 (linux redhat 5) writes a file fic.dat on a NFS SERVER S (RH 5) Another NFS client C2 is waiting for the same file fic.dat (on NFS server S1), and, when "fic.dat" appears, then makes... (8 Replies)
Discussion started by: SolarMax
8 Replies

5. Shell Programming and Scripting

Useless Cat usage

cat ~/text.xt | while read line do echo ${line} | perl -pe 's/(\d+)/localtime($1)/e' done how can i efficiently re-code the above? also, no matter how i run this, i'm not getting the current/correct date. the contents of the "text.xt" looks like this: SERVICES... (2 Replies)
Discussion started by: SkySmart
2 Replies

6. What is on Your Mind?

Fighting useless use of cat

Fighting UUOC cat filename|while read line; do ... with sed 's/cat *\(*\) *|/<\1/g' I found that while loops are converted to <filename while read line; do ... Syntax error! Why syntax error? It would perfectly make sense. Further, read the article how-would-you-like-your-loops-served-today... (5 Replies)
Discussion started by: MadeInGermany
5 Replies
RBASH(1)						      General Commands Manual							  RBASH(1)

NAME
rbash - restricted bash, see bash(1) RESTRICTED SHELL
If bash is started with the name rbash, or the -r option is supplied at invocation, the shell becomes restricted. A restricted shell is used to set up an environment more controlled than the standard shell. It behaves identically to bash with the exception that the follow- ing are disallowed or not performed: o changing directories with cd o setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV o specifying command names containing / o specifying a file name containing a / as an argument to the . builtin command o specifying a filename containing a slash as an argument to the -p option to the hash builtin command o importing function definitions from the shell environment at startup o parsing the value of SHELLOPTS from the shell environment at startup o redirecting output using the >, >|, <>, >&, &>, and >> redirection operators o using the exec builtin command to replace the shell with another command o adding or deleting builtin commands with the -f and -d options to the enable builtin command o using the enable builtin command to enable disabled shell builtins o specifying the -p option to the command builtin command o turning off restricted mode with set +r or set +o restricted. These restrictions are enforced after any startup files are read. When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script. SEE ALSO
bash(1) GNU Bash-4.0 2004 Apr 20 RBASH(1)
All times are GMT -4. The time now is 07:32 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy