10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi fellow linux-ers,
I have a quick question for you. I have the following text, which I would like to modify:
10 121E(121) 16 Jan
34S 132E 24 Feb
42 176E(176) 18 Sep
21S 164E 25 May
15 171W(-171) 09 Jul
How can I do the following 2 modifications using sed and/or awk?
1. in 1st column,... (1 Reply)
Discussion started by: lucshi09
1 Replies
2. Shell Programming and Scripting
Just want to know why when I do the following in sed, the required is not extracted.
echo "ab01cde234" | sed 's/*$//'
result: ab01cde (Which is correct)
echo "ab01cde234" |sed 's/.*\(*\)$/\1/'
result: blank (was expecting 234)
or
echo "ab01cde234" |sed 's/.*\(\)*$/\1/'
result: blank... (6 Replies)
Discussion started by: eo29
6 Replies
3. Shell Programming and Scripting
Hello,
I have the following line in one of my shell scripts. It works fine when the search string($SERACH_STR) exists in the logfile($ALERTLOG) but if the search string does not exist this line errors out at run time. Is there a way to make this line return 0 if it is not able to find the... (4 Replies)
Discussion started by: luft
4 Replies
4. Shell Programming and Scripting
I have a line
EXTDIR=`echo $i | sed 's/\-tar.gz//'`
which looks for files ending in -tar.gz, i would like to increase the functionality so that it looks for .tar.gz files as well as -tar.gz. Do i put the - in square brackets with a dot ? like this
EXTDIR=`echo $i | sed 's/\tar.gz//'`
... (1 Reply)
Discussion started by: hcclnoodles
1 Replies
5. UNIX for Dummies Questions & Answers
from command prompt I did grep two words on a same line for eg: grep abc | grep xyz and I got tht particular line, but I want to know when I vi that file how to directly search for that particular line? I appreciate if any one can provide answer, thanks in advance (2 Replies)
Discussion started by: pkolishetty
2 Replies
6. UNIX for Dummies Questions & Answers
Hi guys
sed -e "s/$<//g"
the $< can allow me to assign an input value to the variable right?
do the double quotes check the previous context? (1 Reply)
Discussion started by: hamoudzz
1 Replies
7. UNIX for Dummies Questions & Answers
hi guys
trying to understand what this line means
sed is a stream editor and i understand that, i have a file already selected
i want to edit so i use -e
sed -e
the next stesp is s/$*
s is a subsititute replacement
sed -e s/$*//g
$ is in reference of the last line
/g makes it... (2 Replies)
Discussion started by: hamoudzz
2 Replies
8. UNIX for Advanced & Expert Users
This "SHOULD" be a simple question,
but looking through several books has turned up nothing,
so I turn once again to the experts!!
How do you vi a file so that you can see special characters.
I believe my /etc/passwd file is being corrupted during an upgrade process, however the files... (6 Replies)
Discussion started by: Recon
6 Replies
9. UNIX for Dummies Questions & Answers
Hello There!
I am trying to write this SIMPLE script in Bourne Shell but I keep on getting syntax errors. Can you see what I am doing wrong? I've done this before but I don't see the difference. I am simply trying to take the day of the week from our system and when the teachers sign on I want... (7 Replies)
Discussion started by: catbad
7 Replies
10. UNIX for Dummies Questions & Answers
Wat is the difference between the cp mv ln etc in /usr/sbin/static
and cp mv ln functions in /usr/bin (4 Replies)
Discussion started by: DPAI
4 Replies
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)