Expressions in double square brackets are described in the Conditional Espressions section of the ksh manual.
Tests in single square brackets are described in "man test".
There is some overlap between the syntax of a Conditional Expression and a Test but they are also quite different when it comes to boolean logic.
In your script example the single square brackets test is preferred.
Hello
I would like to know where there is a difference between these two machines?
HP9000-735/125
HP9000-B132L
What does that all mean?
Okay, HP= Hewlett Packard
But 9000, 725/125, B132L ????
I am asking that question because I am about to buy one for myself, so I can have some fun... (3 Replies)
just wondering what the difference is between 1,$ and /g when doing a substitution in vi. doesn't seem to be much difference from what i can see. (2 Replies)
I think both write at the end of the file ......
but is there a sharp difference between those 2 instruction .....
thank you
this is my 3rd question today forgive me :D (1 Reply)
Hi ..
I am trying to create one function.
It will have two arguments.
Argument1: a,b,d,f,g
Argument2:21212,sfsd,4546,67867,a,asda,b
So the output will be Argument1 - Argument2
which is d,f,g
Can anyone help with this one? (4 Replies)
In the awk I am trying to subtract the difference $3-$2 of each matching $4 before the first _ (underscore) and print that value in $13.
I think the awk will do that, but added comments. What I am not sure off is how to add a line or lines that will add sum each matching $13 value and put it in... (2 Replies)
Discussion started by: cmccabe
2 Replies
LEARN ABOUT PLAN9
tr
TR(1) General Commands Manual TR(1)NAME
tr - translate characters
SYNOPSIS
tr [ -cds ] [ string1 [ string2 ] ]
DESCRIPTION
Tr copies the standard input to the standard output with substitution or deletion of selected characters (runes). Input characters found
in string1 are mapped into the corresponding characters of string2. When string2 is short it is padded to the length of string1 by dupli-
cating its last character. Any combination of the options -cds may be used:
-c Complement string1: replace it with a lexicographically ordered list of all other characters.
-d Delete from input all characters in string1.
-s Squeeze repeated output characters that occur in string2 to single characters.
In either string a noninitial sequence -x, where x is any character (possibly quoted), stands for a range of characters: a possibly empty
sequence of codes running from the successor of the previous code up through the code for x. The character followed by 1, 2 or 3 octal
digits stands for the character whose 16-bit value is given by those digits. The character sequence followed by 1, 2, 3, or 4 hexadecimal
digits stands for the character whose 16-bit value is given by those digits. A followed by any other character stands for that character.
EXAMPLES
Replace all upper-case ASCII letters by lower-case.
tr A-Z a-z <mixed >lower
Create a list of all the words in one per line in where a word is taken to be a maximal string of alphabetics. String2 is given as a
quoted newline.
tr -cs A-Za-z '
' <file1 >file2
SOURCE
/sys/src/cmd/tr.c
SEE ALSO sed(1)TR(1)