If you're using a 1993 or later version of the Korn shell:
will yield:
If you're using a recent bash:
produces the same output.
Both of these suggestions use parameter expansions that are extensions that are allowed, but not specified, by the standards.
This User Gave Thanks to Don Cragun For This Post:
I am trying to strip all leading and trailing spaces of a shell variable using either awk or sed or any other utility, however unscuccessful and need your help.
echo $SH_VAR | command_line Syntax.
The SH_VAR contains embedded spaces which needs to be preserved. I need only for the leading and... (6 Replies)
I have a file that looks like this:
/home/fred/opt/bin
/opt/usr/bin
/usr/sbin/var/opt
I need a way to chop of everything after the last occurance of the / sign including the /. So the file above will now look like this below.
/home/fred/opt
/opt/usr
/usr/sbin/var
I tried using... (6 Replies)
Hello, I am (trying) to write a script that will check to see how many users are logged on to my machine, and if that number is more than 60 I need to kill off all the oldest sessions that are over 60. So far I have been able to check how many users are on and now I am at the part where I have to... (3 Replies)
HI
In my script, i am reading the input from the user and want to find the length of the string.
The input may contain leading spaces. Right now, when leading spaces are there, they are not counted.
Kindly help me
My script is like below. I am using the ksh.
#!/usr/bin/ksh
echo... (2 Replies)
I have a list of servers that I need my script to ping however this list also has the env they belong too such as SIT, PRD, warehouse and so on.
The break character for each section is :
A value in my list would look like this...
brutus.grhq.xxx.com:warehouse
Where brutus.grhq.gfs.com is... (13 Replies)
awk -F"\t" -vOFS="\t" '{print $1"\t-\t-","",$6,$7"\t-"$8"\t-\t-\t"$15}' file.tsv > output.tsv
Using the above command how to remove the string www.abc.com from the $7 value. (7 Replies)
Ok so I know the title was probably confusing so here goes: I have a tarball (gzipped) that has a nested directory structure . For example:
my.tar.gz (contents)
---
------
---------
------------
---------------
... (2 Replies)
Hi... can anyone please tell how do i strip off the leading filename from the wc -l command....
when i fire command
wc -l new1
... its giving output as
14 new1
i want the output as just '14'...
i need to use this value in the calculations in the later part of the script..... (2 Replies)
Hi,
i have a variable which conatins values like 00001,0003,00067,00459.
I want to use the values one by one and in the same form as they are like 00001,0003,00067,00459.
Also can anyone tell me how to increment those numbers by 1,keeping the format as same like 00002,0004,00068,00460.... (5 Replies)
I have a text file with a line of text that contains numbers and text formatted into groups. I need to extract the number that can be either 1,2 or 3 digits long. Then write it to a variable, but i need to remove any leading spaces in the number first.
I can get the numbers out but how to remove... (12 Replies)
Discussion started by: kcpoole
12 Replies
LEARN ABOUT POSIX
regex
regex(1F) FMLI Commands regex(1F)NAME
regex - match patterns against a string
SYNOPSIS
regex [-e] [ -v "string"] [ pattern template] ... pattern [template]
DESCRIPTION
The regex command takes a string from the standard input, and a list of pattern / template pairs, and runs regex() to compare the string
against each pattern until there is a match. When a match occurs, regex writes the corresponding template to the standard output and
returns TRUE. The last (or only) pattern does not need a template. If that is the pattern that matches the string, the function simply
returns TRUE. If no match is found, regex returns FALSE.
The argument pattern is a regular expression of the form described in regex(). In most cases, pattern should be enclosed in single quotes
to turn off special meanings of characters. Note that only the final pattern in the list may lack a template.
The argument template may contain the strings $m0 through $m9, which will be expanded to the part of pattern enclosed in ( ... )$0 through
( ... )$9 constructs (see examples below). Note that if you use this feature, you must be sure to enclose template in single quotes so
that FMLI does not expand $m0 through $m9 at parse time. This feature gives regex much of the power of cut(1), paste(1), and grep(1), and
some of the capabilities of sed(1). If there is no template, the default is $m0$m1$m2$m3$m4$m5$m6$m7$m8$m9.
OPTIONS
The following options are supported:
-e Evaluates the corresponding template and writes the result to the standard output.
-v "string" Uses string instead of the standard input to match against patterns.
EXAMPLES
Example 1: Cutting letters out of a string
To cut the 4th through 8th letters out of a string (this example will output strin and return TRUE):
`regex -v "my string is nice" '^.{3}(.{5})$0' '$m0'`
Example 2: Validating input in a form
In a form, to validate input to field 5 as an integer:
valid=`regex -v "$F5" '^[0-9]+$'`
Example 3: Translating an environment variable in a form
In a form, to translate an environment variable which contains one of the numbers 1, 2, 3, 4, 5 to the letters a, b, c, d, e:
value=`regex -v "$VAR1" 1 a 2 b 3 c 4 d 5 e '.*' 'Error'`
Note the use of the pattern '.*' to mean "anything else".
Example 4: Using backquoted expressions
In the example below, all three lines constitute a single backquoted expression. This expression, by itself, could be put in a menu defini-
tion file. Since backquoted expressions are expanded as they are parsed, and output from a backquoted expression (the cat command, in this
example) becomes part of the definition file being parsed, this expression would read /etc/passwd and make a dynamic menu of all the login
ids on the system.
`cat /etc/passwd | regex '^([^:]*)$0.*$' '
name=$m0
action=`message "$m0 is a user"`'`
DIAGNOSTICS
If none of the patterns match, regex returns FALSE, otherwise TRUE.
NOTES
Patterns and templates must often be enclosed in single quotes to turn off the special meanings of characters. Especially if you use the
$m0 through $m9 variables in the template, since FMLI will expand the variables (usually to "") before regex even sees them.
Single characters in character classes (inside []) must be listed before character ranges, otherwise they will not be recognized. For exam-
ple, [a-zA-Z_/] will not find underscores (_) or slashes (/), but [_/a-zA-Z] will.
The regular expressions accepted by regcmp differ slightly from other utilities (that is, sed, grep, awk, ed, and so forth).
regex with the -e option forces subsequent commands to be ignored. In other words, if a backquoted statement appears as follows:
`regex -e ...; command1; command2`
command1 and command2 would never be executed. However, dividing the expression into two:
`regex -e ...``command1; command2`
would yield the desired result.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO awk(1), cut(1), grep(1), paste(1), sed(1), regcmp(3C), attributes(5)SunOS 5.10 12 Jul 1999 regex(1F)