im new to bash scripting and im just using online tutorials and trial and error. i wanted to write a script to read numbers from a file and find their sum:
when i run this it echoes all the numbers but doesnt give me the correct sum and echo $? returns 0. my console output looks like this:
im not sure why i am getting those syntax errors. thanks.
I am trying to check two variables and if both are blank I want to set a flag:
the_f3_pid=`rsh $target ps -ef | grep "f3.eab" | awk '{print $2}'`
the_f7_pid=`rsh $target ps -ef | grep "f7.eab" | awk '{print $2}'`
if ; then
y=1
fi
I get an error:
./script_name: test: 0403-021 ]... (4 Replies)
hi,
i was trying to club to test condition with if.
if -o ; then
it is giving me error message, i wanted to ask how can we check two condtions with one if. (1 Reply)
1. echo "abc 123 abc" | sed 's/*/X/'
yields -
X 123 abc
Does this mean the "*" operator matches ONLY the first and
the entire token - "abc" and replaces with "X" ?
2. echo "123 abc" | sed 's/*/X/'
yields -
X123 abc
What does this indicate about the "*" operator ?? (7 Replies)
Hi
I want to group
like this but syntactic is not right ...
Thanks
if
Like this below does not work properly ..
if
then
:
else
usage
exit 1
fi (5 Replies)
Hi,
Please clear the 2 questions,
2 Questions,
1) Why the new as a operator? Is there any special reason why it can't be a function like malloc?
2) How are we considering sizeof(),new are as a opearartors? I know + - * / -> , . etc.. are operators, which criteria satisfied by sizeof()... (4 Replies)
All,
THe below is my script , when i use this i am getting nothing . could any one help me to know what is the use of the << operator below
su - $8 << supo
echo "exportsph $2 $1 $3 $4"
exportsph $2 $1 $3 $4
supo
i also tried as individual command su - userid << supo , when i do... (3 Replies)
Hi,
I have the below script executed
arg="dir"
if "$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)
I wrote a little students management program using structs, and when I try to compile it, an error appears:
luke@luke-desktop:~/Desktop/ProgII$ g++ recStudents.cc
recStudents.cc: In function ‘void add(TList&, Tstudent)':
recStudents.cc:114: error: no match for ‘operator' in ‘Slist'Here... (2 Replies)
hi,
I got a requirement to change existing script like below to search additional pattern "DB select". i tried using \| opearator but it is not working :(. Below is the existing code
echo $(cat ${1} |sed -n '/Error in/ {
N
N
N
/Too many/ {
p
... (5 Replies)
Discussion started by: shyamxtasy
5 Replies
LEARN ABOUT PHP
expr
EXPR(1) User Commands EXPR(1)NAME
expr - evaluate expressions
SYNOPSIS
expr EXPRESSION
expr OPTION
DESCRIPTION --help display this help and exit
--version
output version information and exit
Print the value of EXPRESSION to standard output. A blank line below separates increasing precedence groups. EXPRESSION may be:
ARG1 | ARG2
ARG1 if it is neither null nor 0, otherwise ARG2
ARG1 & ARG2
ARG1 if neither argument is null or 0, otherwise 0
ARG1 < ARG2
ARG1 is less than ARG2
ARG1 <= ARG2
ARG1 is less than or equal to ARG2
ARG1 = ARG2
ARG1 is equal to ARG2
ARG1 != ARG2
ARG1 is unequal to ARG2
ARG1 >= ARG2
ARG1 is greater than or equal to ARG2
ARG1 > ARG2
ARG1 is greater than ARG2
ARG1 + ARG2
arithmetic sum of ARG1 and ARG2
ARG1 - ARG2
arithmetic difference of ARG1 and ARG2
ARG1 * ARG2
arithmetic product of ARG1 and ARG2
ARG1 / ARG2
arithmetic quotient of ARG1 divided by ARG2
ARG1 % ARG2
arithmetic remainder of ARG1 divided by ARG2
STRING : REGEXP
anchored pattern match of REGEXP in STRING
match STRING REGEXP
same as STRING : REGEXP
substr STRING POS LENGTH
substring of STRING, POS counted from 1
index STRING CHARS
index in STRING where any CHARS is found, or 0
length STRING
length of STRING
+ TOKEN
interpret TOKEN as a string, even if it is a
keyword like 'match' or an operator like '/'
( EXPRESSION )
value of EXPRESSION
Beware that many operators need to be escaped or quoted for shells. Comparisons are arithmetic if both ARGs are numbers, else lexicograph-
ical. Pattern matches return the string matched between ( and ) or null; if ( and ) are not used, they return the number of characters
matched or 0.
Exit status is 0 if EXPRESSION is neither null nor 0, 1 if EXPRESSION is null or 0, 2 if EXPRESSION is syntactically invalid, and 3 if an
error occurred.
AUTHOR
Written by Mike Parker, James Youngman, and Paul Eggert.
REPORTING BUGS
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Report expr translation bugs to <http://translationproject.org/team/>
COPYRIGHT
Copyright (C) 2017 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
Full documentation at: <http://www.gnu.org/software/coreutils/expr>
or available locally via: info '(coreutils) expr invocation'
GNU coreutils 8.28 January 2018 EXPR(1)