I am still trying to understand how bash code is executed.
Most of us have learnt this over many years, and I know I'm still learning! You are trying to be as knowledgeable in a matter of weeks.
Quote:
Perhaps my perception of code line executing "left to right" is basically wrong.
Look at line #277
Every "manual" I read about using "wc" states it "prints".
and by prints they mean "send its results to the Standard Output stream"
Quote:
I do not need "print" - I need to process what I am used to call "function return value".
OK, I understand 'wc" "prints" most likely to some "stdxxx" - as output of "pipe" .
So how does lineCount value , being at the "front" of the pipe get assigned?
And why is the file to be analyzed at the "end" of the code line?
The problem is bash uses other programs, such as awk, test and wc, the same way languages like C and Python use functions. But as these programs are meant to return their "values" to the terminal for a person to read, you can't just have
Code:
lineCount=wc "somefile"
Process Substitution is used to get over this problem. You know that with Parameter Substitution
Code:
var1="Dave"
var2="${var1}"
the string ${var1} is replaced with the value of var1, i.e. Dave, and assigned to var2. In the same way,
Code:
lines=$(wc -l <myfile)
will replace the string $(wc -l <myfile) with its "value", i.e. the string it attempts to send to the terminal.
I may have asked this before, so forgive OF.
Problem:
I can pass positioning array as -- menu option to whiptail, but it does not show in the whiptail form as an array - only single (first member "lsusb" ) entry / line shows up.
Code:
DynamicEntry=$(whiptail \
--title "DEBUG... (1 Reply)
Hi. May somebody help me with this.
I´m trying to tabulate the following input file, but the desired output I´m getting is incorrect.
I have access to GNU/LINUX (Ubuntu) and Cygwin
Input file
STAGE = 1
ID = 0
NAME = JFMSC
TYPE = MLRR
DFRUL = PERMISSION
ADDR = 1001
RRUL =... (10 Replies)
Hi Gurus,
my current code like below:
nawk '{f1 = (NF>1)?$1:""}{print f1, $NF}'|sed -e 's/s(/,/g;s/)//g;s/ *,/,/'|nawk -F"," '{ab}END{for (i in b) if (!(i in a))print i}'
I have file like below. (this is autosys job dependencies)
the job with s() is dependencies, the job without s() is... (10 Replies)
I have a postgres sql statement that is the following:
select age from students;
which gives me the entries:
Age
---
10
15
13
12
9
14
10
which is about 7 rows of data.
Now what I would like to do with this is use a shell script to create an array age. As a results... (3 Replies)
Hello All,
Maybe I'm Missing something here but I have NOOO idea what the heck is going on with this....?
I have a Variable that contains a PATTERN of what I'm considering "Illegal Characters". So what I'm doing is looping
through a string containing some of these "Illegal Characters". Now... (5 Replies)
I am trying to get userinput from stdin and store the lines in an array.
If i do this:
using a char **list to store strings
allocate memory to it
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv)
{
char *prog = argv;
char **linelist;
int... (5 Replies)
I've been struggling with this for quite some time. I decided I should get some help with this. Nothing is working. I'm getting a segmentation fault or out of bounds error when I try to load the entries in the for loop.I'm really frustrated. :mad: Compiling isn't the problem. It's crapping out on... (5 Replies)
Hi Forum,
I am struggling with the for loop in shell script.
Let me explain what is needed in the script.
I have a file which will conatin some strings like
file1
place1
place2
place3
checkpoint
some other text
some more text
Now what my requirement is
the words ... (2 Replies)
Hi
I need a better idea to implementing following in my code.
I need to store 80 long strings that will be used to display one by one in my GUI application. now i am storing those 80 long string in following two dimentational array.
uchar vpn_alm_long_str={ }
each index will be an... (1 Reply)
