EXPR(1) General Commands Manual EXPR(1)NAME
expr - evaluate experession
SYNOPSIS
expr arg ...
EXAMPLES
x=`expr + 1` # Add 1 to shell variable x
DESCRIPTION
Expr computes the value of its argument and writes the result on standard output. The valid operators, in order of increasing precedence,
are listed below. Operators grouped by {...} have the same precedence. The operators are: |, &, {<, <=, ==, !=, >=, >}, {+, -}, *, /, %,
and :. Parentheses are permitted.
SEE ALSO sh(1), test(1).
EXPR(1)
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expr(1) General Commands Manual expr(1)Name
expr - evaluate expressions
Syntax
expr arg...
Description
The arguments are taken as an expression. After evaluation, the result is written on the standard output. Each token of the expression is
a separate argument.
The operators and keywords are listed below. The list is in order of increasing precedence, with equal precedence operators grouped.
expr | expr Yields the first expr if it is neither null nor 0. Otherwise yields the second expr.
expr & expr Yields the first expr if neither expr is null or 0. Otherwise yields 0.
expr relop expr The relop is one of < <= = != >= > and yields 1 if the indicated comparison is true, '0' if false. The comparison is
numeric if both expr are integers, otherwise lexicographic.
expr + expr
expr - expr
Yields addition or subtraction of the arguments.
expr * expr
expr / expr
expr % expr
Yields multiplication, division, or remainder of the arguments.
expr : expr The matching operator compares the string first argument with the regular expression second argument; regular expres-
sion syntax is the same as that of The (...) pattern symbols can be used to select a portion of the first argument.
Otherwise, the matching operator yields the number of characters matched ('0' on failure).
( expr ) parentheses for grouping.
Examples
The first example adds 1 to the Shell variable a:
a=`expr $a + 1`
The second example finds the file name part (least significant part) of the pathname stored in variable a,
expr $a : '.*/(.*)' '|' $a
Note the quoted Shell metacharacters.
Diagnostics
The command returns the following exit codes:
0 The expression is neither null nor '0'.
1 The expression is null or '0'.
2 The expression is invalid.
See Alsoed(1), sh(1), test(1)expr(1)
Basically i have done created the script below, and it functions ok, it prints the access rights the user has. But i need it to print the group permissions, and other permissions, it would also be helpful if i could print the permissions in numeric form aswell, if it is possible. I have looked in... (50 Replies)
May be a simple question for experts here....
I need to get the list of files older than 30 days in the current folder. I tried "find", but it searches recursively in all the sub directories.
Can I restrict the recursive search and extract the files only from current directory ? (18 Replies)
Hi,
This question may be quite newbish.
I've stored a few files on my Unix system and am wondering how to search for their contents (i.e. I input the keyword and get a list of files with this keyword)
I'd then like to put it on my website (php).
I thought of find and grep, but am not... (19 Replies)
Hi
I have a variable whose value is like this
i=/test/test1/test2/myfile.cd.070505123457
i would like to have the value of myfile.cd stored into another variable
my attempt is
test=${i##*/} ;echo $test ##and i get
myfile.cd.070505123457
since what i wnat is myfile.cd i try this... (19 Replies)
Hi there
I am running a script which requires the input of a MAC address from the user and was loooking for a regex that will verify the user has inputted a full 12 digit valid MAC with colons
Ive seen a few on some sites that look huge and was wondering if anybody had a one liner (or as... (21 Replies)
hi all,
i need an urgent help for writing a shell script which will extract out and print a substring which is the shortest substring from the given string where first and last character of that substring will be given by the user.
for e.g.
if str="abcdpqracdpqaserd"
now if the user gives 'a'... (18 Replies)
This part of script look of a pattern in a file ($file) and should print the file names of the file if the pattern is found between min and max.
I don't know very well AWK, so i written this script thinking that $0 is the current field, but maybe is the current record, not the field. That may be... (22 Replies)
Hello Unix gurus,
I am new to Unix. I am working on some dummy project which involves unix scripting.
I have a query :
There is a file Number.dat which is of form say
AAA|123|4563|animal
AAA|1234|45634|animal2
BBB|123444|456312|bird
BBB|123445|456313|bird2
Here AAA,BBB are... (29 Replies)
can someone help me with the find and replace command.
I have a input file which is in the below format:
0011200ALN00000000009EGYPT 000000000000199900000
0011200ALN00000000009EGYPT 000000000000199900000
0011200ALN00000000008EGYPT 000000000000199800000
0011200ALN00000000009EGYPT ... (20 Replies)
I am running AIX 5.3 using the Korn Shell. I am reading file names from a file, as an example:
E0801260
E0824349
E0925345
EMPMSTR
statement "num=$(expr substr "$DDNAME" 4 2)
extracts the numeric values fine. But when I het the last entry, it returns num=MS, but I get an error... (19 Replies)
I need a quick expression to be able to pull out all the data in a text file that looks like "http:// some random url etc" So it should grab any string that begins with "http:// and ends with " There are other double quotes in the file but I only want the ones that start with "http:// and the... (31 Replies)
Hi ,
I am having an issue with the Awk script to insert newline for a regular expression match
Having a file like this
FILE1
####################
RXOER , RXERA , RXERC , RXERD
.RXEA(RXBSN), RXERD , REXCD
input RXEGT
buffer RXETRY
#######################
Want to match the RXE... (38 Replies)
I am trying to grep for a particular text (Do action on cell BL330) in a text file(sample.gz) which is searched in the content filtered by date+timestamp (2016-09-14 01:09:56,796 to 2016-09-15 04:10:29,719) on a remote machine and finally write the output into a output file on a local machine.
... (23 Replies)
Hi folks,
I have a script where i am trying to calc the difference between two epoch dates and then have a condition based on the resultant value.
When I run the script it keeps complaining;
expr: syntax error
./testdiff.sh: line 11: syntax error in conditional expression
./testdiff.sh:... (25 Replies)
I was looking through the topics and I wasn't sure if this was the best place to post this question:
I was wondering, out of curiosity, which software everyone was using to code their scripts in. I do mostly sh/ksh and my favorite has always been EditPlus because it is small, fast, yet powerful.... (409 Replies)