Bash script, get number of physical cores as number and iterate
I wrote a script that shows a number of physical cores of the machine. However, I would like the result to be a number, not a string.
Here's the script:
phycores=echo $sudoPW | cat /proc/cpuinfo | grep -m 1 "cpu cores" | awk '{print $ 4;}'
echo $phycores
for i in {1..$phycores}
do
echo "Core $i"
done
bash cpu script
asked Dec 10 at 13:25
Brian Brown
92414
add a comment |
I wrote a script that shows a number of physical cores of the machine. However, I would like the result to be a number, not a string.
Here's the script:
phycores=echo $sudoPW | cat /proc/cpuinfo | grep -m 1 "cpu cores" | awk '{print $ 4;}'
echo $phycores
for i in {1..$phycores}
do
echo "Core $i"
done
bash cpu script
asked Dec 10 at 13:25
Brian Brown
92414
bashconvert on the fly strings to numbers. so you should not concern about this
– Romeo Ninov
Dec 10 at 13:27
But why am I getting a newline while trying to echo the$phycores? It shows 2 [Enter], not only 2
– Brian Brown
Dec 10 at 13:29
What do you mean by "physical cores"? What you're trying to extract fromcpuinfomay not be what you want. See this question.
– Kamil Maciorowski
Dec 10 at 13:41
1
bash doesn't have the notion of numbers. Everything is a string or an array of strings.
– gronostaj
Dec 10 at 13:54
@BrianBrown If you only need the "number" then strip the trailing newlinenr,n
– dmb
Dec 10 at 14:20
add a comment |
I wrote a script that shows a number of physical cores of the machine. However, I would like the result to be a number, not a string.
Here's the script:
phycores=echo $sudoPW | cat /proc/cpuinfo | grep -m 1 "cpu cores" | awk '{print $ 4;}'
echo $phycores
for i in {1..$phycores}
do
echo "Core $i"
done
bash cpu script
asked Dec 10 at 13:25
Brian Brown
92414
I wrote a script that shows a number of physical cores of the machine. However, I would like the result to be a number, not a string.
Here's the script:
phycores=echo $sudoPW | cat /proc/cpuinfo | grep -m 1 "cpu cores" | awk '{print $ 4;}'
echo $phycores
for i in {1..$phycores}
do
echo "Core $i"
done
bash cpu script
bash cpu script
asked Dec 10 at 13:25
Brian Brown
92414
asked Dec 10 at 13:25
Brian Brown
92414
edited Dec 10 at 14:07
asked Dec 10 at 13:25
Brian Brown
92414
asked Dec 10 at 13:25
Brian Brown
92414
asked Dec 10 at 13:25
Brian Brown
92414
92414
bashconvert on the fly strings to numbers. so you should not concern about this
– Romeo Ninov
Dec 10 at 13:27
But why am I getting a newline while trying to echo the$phycores? It shows 2 [Enter], not only 2
– Brian Brown
Dec 10 at 13:29
What do you mean by "physical cores"? What you're trying to extract fromcpuinfomay not be what you want. See this question.
– Kamil Maciorowski
Dec 10 at 13:41
1
bash doesn't have the notion of numbers. Everything is a string or an array of strings.
– gronostaj
Dec 10 at 13:54
@BrianBrown If you only need the "number" then strip the trailing newlinenr,n
– dmb
Dec 10 at 14:20
add a comment |
bashconvert on the fly strings to numbers. so you should not concern about this
– Romeo Ninov
Dec 10 at 13:27
But why am I getting a newline while trying to echo the$phycores? It shows 2 [Enter], not only 2
– Brian Brown
Dec 10 at 13:29
What do you mean by "physical cores"? What you're trying to extract fromcpuinfomay not be what you want. See this question.
– Kamil Maciorowski
Dec 10 at 13:41
1
bash doesn't have the notion of numbers. Everything is a string or an array of strings.
– gronostaj
Dec 10 at 13:54
@BrianBrown If you only need the "number" then strip the trailing newlinenr,n
– dmb
Dec 10 at 14:20
bash convert on the fly strings to numbers. so you should not concern about this– Romeo Ninov
Dec 10 at 13:27
bash convert on the fly strings to numbers. so you should not concern about this– Romeo Ninov
Dec 10 at 13:27
But why am I getting a newline while trying to echo the
$phycores? It shows 2 [Enter], not only 2– Brian Brown
Dec 10 at 13:29
But why am I getting a newline while trying to echo the
$phycores? It shows 2 [Enter], not only 2– Brian Brown
Dec 10 at 13:29
What do you mean by "physical cores"? What you're trying to extract from
cpuinfo may not be what you want. See this question.– Kamil Maciorowski
Dec 10 at 13:41
What do you mean by "physical cores"? What you're trying to extract from
cpuinfo may not be what you want. See this question.– Kamil Maciorowski
Dec 10 at 13:41
1
1
bash doesn't have the notion of numbers. Everything is a string or an array of strings.
– gronostaj
Dec 10 at 13:54
bash doesn't have the notion of numbers. Everything is a string or an array of strings.
– gronostaj
Dec 10 at 13:54
@BrianBrown If you only need the "number" then strip the trailing newline
nr, n– dmb
Dec 10 at 14:20
@BrianBrown If you only need the "number" then strip the trailing newline
nr, n– dmb
Dec 10 at 14:20
add a comment |
1 Answer
1
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oldest
votes
I'm spotting a few issues:
Why the
echo $sudoPWpiped to cat? cat ignores it without a-somewhere.And
$phycoresdoesn't get set without backticks or$()that can't be the actual script you're running, and it still sets $phycores to a number with a newline?The
{1..n}construct doesn't work with a variable, if your$phycoreswere 4 then it just sets the$ivariable to{1..4}. See this Q on stackoverflow for more details. (A newline in$phycoresshouldn't matter)
Anyway, this should be a more working script
phycores=$(echo $sudoPW|cat - /proc/cpuinfo|grep -m 1 "cpu cores"|awk '{print $ 4;}')
echo $phycores
for ((i=1;i<=phycores;++i))
do
echo "Core $i"
done
answered Dec 10 at 15:31
Xen2050
9,93431536
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
add a comment |
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1 Answer
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active
oldest
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1 Answer
1
active
oldest
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oldest
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active
oldest
votes
I'm spotting a few issues:
Why the
echo $sudoPWpiped to cat? cat ignores it without a-somewhere.And
$phycoresdoesn't get set without backticks or$()that can't be the actual script you're running, and it still sets $phycores to a number with a newline?The
{1..n}construct doesn't work with a variable, if your$phycoreswere 4 then it just sets the$ivariable to{1..4}. See this Q on stackoverflow for more details. (A newline in$phycoresshouldn't matter)
Anyway, this should be a more working script
phycores=$(echo $sudoPW|cat - /proc/cpuinfo|grep -m 1 "cpu cores"|awk '{print $ 4;}')
echo $phycores
for ((i=1;i<=phycores;++i))
do
echo "Core $i"
done
answered Dec 10 at 15:31
Xen2050
9,93431536
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
add a comment |
I'm spotting a few issues:
Why the
echo $sudoPWpiped to cat? cat ignores it without a-somewhere.And
$phycoresdoesn't get set without backticks or$()that can't be the actual script you're running, and it still sets $phycores to a number with a newline?The
{1..n}construct doesn't work with a variable, if your$phycoreswere 4 then it just sets the$ivariable to{1..4}. See this Q on stackoverflow for more details. (A newline in$phycoresshouldn't matter)
Anyway, this should be a more working script
phycores=$(echo $sudoPW|cat - /proc/cpuinfo|grep -m 1 "cpu cores"|awk '{print $ 4;}')
echo $phycores
for ((i=1;i<=phycores;++i))
do
echo "Core $i"
done
answered Dec 10 at 15:31
Xen2050
9,93431536
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
add a comment |
I'm spotting a few issues:
Why the
echo $sudoPWpiped to cat? cat ignores it without a-somewhere.And
$phycoresdoesn't get set without backticks or$()that can't be the actual script you're running, and it still sets $phycores to a number with a newline?The
{1..n}construct doesn't work with a variable, if your$phycoreswere 4 then it just sets the$ivariable to{1..4}. See this Q on stackoverflow for more details. (A newline in$phycoresshouldn't matter)
Anyway, this should be a more working script
phycores=$(echo $sudoPW|cat - /proc/cpuinfo|grep -m 1 "cpu cores"|awk '{print $ 4;}')
echo $phycores
for ((i=1;i<=phycores;++i))
do
echo "Core $i"
done
answered Dec 10 at 15:31
Xen2050
9,93431536
I'm spotting a few issues:
Why the
echo $sudoPWpiped to cat? cat ignores it without a-somewhere.And
$phycoresdoesn't get set without backticks or$()that can't be the actual script you're running, and it still sets $phycores to a number with a newline?The
{1..n}construct doesn't work with a variable, if your$phycoreswere 4 then it just sets the$ivariable to{1..4}. See this Q on stackoverflow for more details. (A newline in$phycoresshouldn't matter)
Anyway, this should be a more working script
phycores=$(echo $sudoPW|cat - /proc/cpuinfo|grep -m 1 "cpu cores"|awk '{print $ 4;}')
echo $phycores
for ((i=1;i<=phycores;++i))
do
echo "Core $i"
done
answered Dec 10 at 15:31
Xen2050
9,93431536
answered Dec 10 at 15:31
Xen2050
9,93431536
answered Dec 10 at 15:31
Xen2050
9,93431536
answered Dec 10 at 15:31
Xen2050
9,93431536
9,93431536
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
add a comment |
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
In absence of a Linux tag, :) I'll add the (simpler) FreeBSD equivalent: phycores=$(sysctl -n hw.ncpu)
– Jim L.
Dec 12 at 22:57
add a comment |
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bashconvert on the fly strings to numbers. so you should not concern about this– Romeo Ninov
Dec 10 at 13:27
But why am I getting a newline while trying to echo the
$phycores? It shows 2 [Enter], not only 2– Brian Brown
Dec 10 at 13:29
What do you mean by "physical cores"? What you're trying to extract from
cpuinfomay not be what you want. See this question.– Kamil Maciorowski
Dec 10 at 13:41
1
bash doesn't have the notion of numbers. Everything is a string or an array of strings.
– gronostaj
Dec 10 at 13:54
@BrianBrown If you only need the "number" then strip the trailing newline
nr,n– dmb
Dec 10 at 14:20