9 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hello,
I have compiled a script but I have stucked at one point.
Each line contains two pcs of % value and what I want to do is to delete any line if both % values are zero.
data:
expected output:
ow3 should be deleted as both percentage value in related line are equal to zero.
... (2 Replies)
Discussion started by: baris35
2 Replies
2. Shell Programming and Scripting
Hello everyone,
I have a requirement as shown below. I need to delete consecutive same values from the source file and give it as output file.
Source:
a,b,c,d,e,e,f,g
Target:
a,b,c,d,f,g
The repeating value "e" should be deleted from the file completely. How can I achieve this... (14 Replies)
Discussion started by: vamsikrishna928
14 Replies
3. UNIX for Dummies Questions & Answers
Hi,
I have a tab delimited text file where some lines have the string "NA" in the second column. For these lines, I want to replace NA with the value in the first column, the symbol underscore followed by the value in the fourth column. How do I go about doing that? Thanks!
Input:
1 ... (3 Replies)
Discussion started by: evelibertine
3 Replies
4. UNIX for Dummies Questions & Answers
Hi there can anyone help me please. I want to make a program to check if the executable file specified by the user exists in the directory.
When I run this program particulary these lines of code does not work:
if ("$fi" == "$name") then where It checks whether the specified file is equal to the... (1 Reply)
Discussion started by: FUTURE_EINSTEIN
1 Replies
5. Shell Programming and Scripting
How do I go about amending this simple script that prompts for a yes/no response so that if neither Y or N are entered it will loop back back to the original prompt
#!/bin/ksh
echo "Enter yes of no"
read answer
if
then
echo "You selected yes"
elif
then
echo "You selected no"
elif... (5 Replies)
Discussion started by: gmears
5 Replies
6. Shell Programming and Scripting
Hi all
I have this script that i have written in some logging for but i do not want it to log for all option, i have used Getopt::Long 2.11 to allow differnt switches but i only want logging on one type of switch
this is my code but it does not like the ne (not equals)
i do not wnat the... (7 Replies)
Discussion started by: ab52
7 Replies
7. Shell Programming and Scripting
Hi all
I am trying to scan a file that has 3 columns:
red blue 123351
red blue 848655
red blue 126354
red blue 023158
black white 654896
red blue 650884
I want an output that sums the rows that have matching columns 1 and 2 :wall:
red blue has 5 entries
black white has 1 entry
... (4 Replies)
Discussion started by: reno
4 Replies
8. Shell Programming and Scripting
while + and equal to zero ; then
what to punt instead of phrase and equal to zero.
it's bash
thank you in advance (1 Reply)
Discussion started by: losh
1 Replies
9. Shell Programming and Scripting
Hi,
I have the below script executed
arg="dir"
if "$arg" = "dir"
then
echo "true"
else
echo "false"
fi
Please let me know what happens in the if command.
My output is:
dir: dir: No such file or directory
false
which is not the desired output.
When i used test command... (1 Reply)
Discussion started by: anijan
1 Replies
GREP(1) General Commands Manual GREP(1)
NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output; unless the -h flag is used, the file name is shown if there is more than one input file.
Grep patterns are limited regular expressions in the style of ed(1); it uses a compact nondeterministic algorithm. Egrep patterns are full
regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. Fgrep patterns are fixed strings; it
is fast and compact.
The following options are recognized.
-v All lines but those matching are printed.
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-s No output is produced, only status.
-h Do not print filename headers with output lines.
-y Lower case letters in the pattern will also match upper case letters in the input (grep only).
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
Care should be taken when using the characters $ * [ ^ | ? ' " ( ) and in the expression as they are also meaningful to the Shell. It is
safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character matches that character.
The character ^ ($) matches the beginning (end) of a line.
A . matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by * (+, ?) matches a sequence of 0 or more (1 or more, 0 or 1) matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
SEE ALSO
ed(1), sed(1), sh(1)
DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
BUGS
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
Lines are limited to 256 characters; longer lines are truncated.
GREP(1)