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Old 06-07-2008, 10:57 AM   #1
wrapster
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a question on all shell commands???


Hi all,
I have a very basic question to ask...
do not mind
How do you figure out if a command is a "built in"(in any shell) or not?

PSlease dont flame me!!!
 
Old 06-07-2008, 11:05 AM   #2
pixellany
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"man bash" gives you all the built-ins.

OR

Look for the command in /bin or /sbin. If it's not there, its a built-in
 
Old 06-07-2008, 11:44 AM   #3
crigaeha
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the type command. binaries need to be in users path.
as in:
type bash
type type
type !

It also tells you if a command is hashed or an alias.

Last edited by crigaeha; 06-07-2008 at 11:47 AM.
 
Old 06-07-2008, 12:19 PM   #4
wrapster
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I tried,
type awk
awk is /usr/bin/awk
however a man awk,
gives me its presence even in /usr/xpg4/bin/awk
Similarly there are many commands that are present in 2 or more dirs..
why is it?
Is it dependent on type of operation that is specified on that command?
eg,
Assuming that ls is in /usr/bin and /usr/xpg4/bin
is it that,
when i do ls -l it reads from /usr/bin/
and ls -a reads it from /usr/xpg4/bin

type ls
ls is hashed (/usr/bin/ls)
What does hashed mean?
Also the same was the result when i did a "type touch"
Could i know what these mean?

Thanks

Last edited by wrapster; 06-07-2008 at 12:34 PM.
 
Old 06-07-2008, 04:32 PM   #5
jlliagre
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Quote:
Originally Posted by wrapster View Post
Similarly there are many commands that are present in 2 or more dirs..
why is it?
Usually to comply with differing standards.
Quote:
Is it dependent on type of operation that is specified on that command?
eg,
Assuming that ls is in /usr/bin and /usr/xpg4/bin
is it that,
when i do ls -l it reads from /usr/bin/
and ls -a reads it from /usr/xpg4/bin
No. The command that will be executed is the first one found in your PATH.
Quote:
type ls
ls is hashed (/usr/bin/ls)
What does hashed mean?
It means the shell has recorded the command location to speed up further execution.

Run the "hash" command to see which commands are remembered.
 
Old 06-07-2008, 05:02 PM   #6
Tinkster
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Quote:
Originally Posted by wrapster View Post
Assuming that ls is in /usr/bin and /usr/xpg4/bin
is it that,
when i do ls -l it reads from /usr/bin/
and ls -a reads it from /usr/xpg4/bin
...
type ls
ls is hashed (/usr/bin/ls)
What does hashed mean?

Are you on openSolaris or something?
 
  


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