I'm trying to execute this simple script in solaris.
I want to sort(numeric) the filenames of the files in source directory and copy the file one by one to another directory. And, I want to print a message after copying every 100 files.
#!/bin/bash
count=0
for i in `ls | sort -n`
do
cp $i ../target
count = $((count+1))
if[ $count%100 -eq 0 ]
then
echo $count files copied
sleep 1
fi
done
this is not working. I tried different things after searching in net.
I get errors like these -
syntax error at line 8: '(' unexpected.
syntax error at line 10: 'then' unexpected.
syntax error at line 13: 'fi' unexpected etc.
What is the problem with this script?
bash version - GNU bash, version 3.00.16(1)-release (sparc-sun-solaris2.10)
The basic problem with the script is spacing. You have spaces where you shouldn't have them:
(wrong) count = $((count+1))
(right) count=$((count+1))
(better) ((count++))
and you're missing spaces where you need them:
(wrong) if[ $count%100 -eq 0 ]
(right) if [ $((count % 100)) -eq 0 ]
(better) if ((count % 100 == 0))
count = $((count+1)) tries to run the command count passing it two arguments, = and the value of count+1. if[ ... tries to run the command if[ because [ is a valid word character; it doesn't automatically start a new token.
Having said all that, I'm puzzled by the unexpected ( error message. Could your bash be too old to recognize $(( syntax? Possibly. It's a very old bash.
count=$((count+1))
if [ `echo $count % 100 | bc` -eq 0 ]
Make these corrections.
Edit: Please try
count=`expr $count + 1`
I see a few errors here. First, you need double quotes around $i in case they have special characters.
Second, you shouldn't ever use
for i in `ls | sort -n`
Instead, try the following
ls -1 | sort -n | while read i
Third, change your if statement to
if ((count%5 == 0))
The (( syntax is bash is made just for integer math.
Fourth, change your counter increment to
((count++))
This is more concise. Also, the space in your version may break things. Remember, spaces matter.
Related
I just started learning Bash scripting and i have to do a program that separate between one bit map image to two (the image is broken), I already found on the web how to write loops and statements
but i don't know why my if statement is always goes to the else.
the if is modulo by 2 thats equals to 0
here is the following code
#!/bin/sh
OUTPUT="$(hexdump -v -e '/1 "%02X\n"' merge.bmp)"
echo $OUTPUT
vars=0
count=1
touch one
touch two
for i in $OUTPUT
do
if (($vars%2==0))
then
echo "1"
else
echo "2"
fi
vars=$((vars+count))
done
in the terminal the following error is
./q3.sh: 14: ./q3.sh: 2885%2==0: not found
2
i really don't know why the if always print 2
The shebang line is wrong, it should be:
#!/bin/bash
((expression)) is a bash extension, not available in sh.
The /bin/sh version of the (()) bashism is this:
if test $(($vars % 2)) -eq 0; then
echo "1"
...
fi
Since $(()) knows about variable names, you may even drop the dollar and write
if test $((vars % 2)) -eq 0; then
echo "1"
...
fi
my script check if the arguments are files or folders
if it is a file, he count the number of lines
after that, if the number of lines is great then 20 or less he do some instructions
the problem is in this instructionn= cat $a | wc -l
My script:
#!/usr/bin/env bash
echo 'Hello this is the test of' `date`
echo 'arguments number is ' $#
if [ $# -eq 4 ]
then
for a in $#
do
if [ -d $a ]
then
ls $a > /tmp/contenu
echo "contenu modified"
elif [ -f $a ]
then
# this instruction must set a numeric value into n
echo "my bad instruction"
n= cat $a | wc -l
echo "number of lines = " $n
# using the numeric value in a test (n must be numeric and takes the number of lines in the current file)
if [ $n -eq 0 ]
then
echo "empty file"
elif [ $n -gt 20 ]
then
echo ` head -n 10 $a `
else
cat $a
fi
else
echo "no file or directory found"
fi
done
else
echo "args number must be 4"
fi
This is the output of the execution of the incorrect instruction
my bad instruction
5
number of lines =
ExamenEx2.sh: line 19: [: -eq : opérateur unaire attendu
The line n= cat $a | wc -l is an offending instruction. Always remember that bash shell scripting is extremely case-sensitive. Your command is interpreted by the shell as having to run two separate commands
n= cat $a | wc -l
#^^ ^^^^^^^^^^^^^^
#1 2
The first part just stores an empty string to the variable n and the next prints the line count of the file stored in variable a. Notice that the shell does not throw errors for this. Because it is not violating the syntax (just the semantics are wrong). But the line count is never assigned to the variable n.
The error is seen when the conditional if [ $n -eq 0 ] is hit when you are doing a comparison with an empty variable on the LHS.
You wanted to run a command and store its output, you need command-substitution($(..)) for that. Assuming the $a contains a name of a file just do
n=$(wc -l < "$a")
Note, that I've removed the useless cat usage and piping it to wc. But wc can read from an input stream directly.
Also note that you have multiple bad practices in your script. Remember to do the following
Always double-quote the shell variables - "$#", "$#", [ -f "$a" ], [ -d "$a" ]
Don't use the `` for command-substitution, because it is not easily nestable and you might have issues related to quoting also.
You can use conditional expression [[ if you are sure if the script is running under bash in which a variable containing spaces can be used without quoting on the LHS
This question already has answers here:
Why should there be spaces around '[' and ']' in Bash?
(5 answers)
Closed 5 years ago.
I am fairly new to bash scripting and am struggling with some if-statement syntax.
I have currently written up the following loop:
for (( i = 2; i < $# - 1; i++)); do
if [ $i -ne 0]; then
if [ $i -ne 1]; then
echo "$i was not 1 or 0. Please correct this then try again."
exit 1;
fi
fi
done
This code is supposed to test whether any arguments after the first are either a 1 or a 0.
While the following errors are printed:
./blink.sh: line 36: [: missing `]'
./blink.sh: line 36: [: missing `]'
...the code actually runs fine afterwards (so the errors don't kill the program).
My understanding, however, is that in bash, you put spaces before and after the expression inside the if statement. So this:
if [ $i -ne 0]; then
Becomes:
if [ $i -ne 0 ]; then
However, running this code produces the following:
2 was not 1 or 0. Please correct this then try again.
The main issue I am having with this stems from not understanding how to indirectly reference the positional arguments provided by the execution command. As such, I am confused as to what syntax must be altered to call the objects the arguments point to (in this case, hopefully either a 1 or a 0) rather than the position of the arguments themselves (argument 1, 2, 3...).
Thanks!
EDIT: Altering the question to better fit the advice #randomir provided and clear up what the actual question entails
Based on:
This code is supposed to test whether any arguments after the first are either a 1 or a 0.
I'm assuming you're trying to access positional arguments $2, $3, etc. To make your for loop solution work, you would have to use an indirect reference: ${!i} (see shell parameter expansion). For example, this should work:
#!/bin/bash
for (( i = 2; i <= $#; i++ )); do
if [[ ${!i} -ne 0 ]]; then
if [[ ${!i} -ne 1 ]]; then
echo "$i was not 1 or 0. Please correct this then try again."
exit 1;
fi
fi
done
Note the i running from 2 to number of arguments $#. Also, note the use of recommended and less error-prone [[ .. ]] instead of [ .. ] (otherwise you would have to write [ "${!i}" -ne 0 ], etc).
A simpler solution which avoids the unnecessary indirect referencing looks like this:
#!/bin/bash
while [[ $2 ]]; do
if (( $2 != 0 && $2 != 1 )); then
echo "$2 is neither 0, nor 1"
exit 1
fi
shift
done
We start checking the second argument ($2), use the arithmetic expression (( expr )) testing of value of the second argument, and shift positional arguments to the left by 1 at each iteration (now $3 becomes $2, etc).
Can someone point out what is wrong with the output.
for i in {0..127} ; do
echo -n [$i]
if [ $i*$j%8 -eq 0 ]; then
echo "\n"
fi
mytool -c "read 0x1540:0xa0:$i*$j"
done
I am trying to format the output into rows containing 8 items each.
I tried the suggestion below and modified my code to
for i in {0..8} ; for j in {0..16}; do
echo -n [$i*$j]
if [[ $i*$j%8 == 0 ]]; then
echo
fi
mytool -c "read 0x1540:0xa0:$i*$j"
done
Above with for i in {0..8} ; for j in {0..16}
I am expecting this to be a nested for loop.I am not very sure if this is how I do a nested loop in bash.
Still the output is not as I expect it.
My output looks like
[0]0x3
[1]0x4
[2]0x21
[3]0x1
[4]0x0
[5]0x0
[6]0x4
[7]0x41
[8]0x84
[9]0x80
[10]0x0
[11]0x0
[12]0x3
[13]0x0
[14]0x43
[15]0x49
[16]0x53
[17]0x43
[18]0x4f
[19]0x2d
[20]0x49
[21]0x4e
[22]0x43
[23]0x20
[24]0x0
[25]0x0
[26]0x9
[27]0x3a
[28]0x37
[29]0x34
[30]0x39
[31]0x34
I want [0] to [7] in ROW1
[8] to [15] in ROW2
and so on.
Use (( )) if you want to do math.
if ((i * j % 8 == 0)); then
Given your problem description I suggest a bit of a rewrite.
for i in {0..15}; do
for j in {0..7}; do
echo -n "[$((i * 8 + j))]"
mytool -c "read 0x1540:0xa0:$i*$j"
done
echo
done
The test command ([ is an alias for test, not syntax) requires the expression to be built up from multiple arguments. This means spaces are critical to separate operators and operands. Since each part is a separate argument, you also need to quote the * so that the shell does not expand it as a file glob prior to calling test/[.
if [ "$i" "*" "$j" % 8 -eq 0 ]; then
The test command expects 7 separate arguments here: $i, *, $j, %, -eq, and 0, which it then assembles into an expression to evaluate. It will not parse an arbitrary string into an expression.
As noted by John Kugelman, there are easier ways to accomplish such arithmetic in bash.
I have the following korn script:
#!/bin/ksh
TAPPDATADIR=/hp/qa02/App/IPHSLDI/Data
echo $TAPPDATADIR
if [[ls $TAPPDATADIR/zip_file_MD5_checksum*.txt | wc -l > 1]]
then
exit "asdf"
fi
When I attempt to run it I get:
/hp/qa02/App/IPHSLDI/Data
./iftest.ksh: line 7: [[ls: not found
Why isn't my if statement working?
I'm trying to see if there are multiple checksum files in the Data directory. If there are I want to exit the script.
There are several problems:
There shouldn't be any spaces around = in the assignment.
You need spaces around [[ and ]] in the if statement.
To substitute the result of a command into the test expression, you need to use backticks or $(...).
The parameter to exit should be a number, I think you just want to echo the string.
> performs string comparison, you have to use -gt to perform numeric comparison.
So the full script should be:
#!/bin/ksh
TAPPDATADIR=/hp/qa02/App/IPHSLDI/Data
echo $TAPPDATADIR
if [[ $(ls $TAPPDATADIR/zip_file_MD5_checksum*.txt | wc -l) -gt 1 ]]
then
echo "asdf"
fi