Iterating over files in Bash and obtaining the index and the counts
The proper way to iterate over files in a directory in Bash is using "for loop" and glob as following:
for f in *.jpg; do
echo "- Processing file: $f"
done
But how can I retrieve the total count of the files and the current index of the loop interaction? I need the total count, not the cumulative count to show the progress.
shell-script
add a comment |
The proper way to iterate over files in a directory in Bash is using "for loop" and glob as following:
for f in *.jpg; do
echo "- Processing file: $f"
done
But how can I retrieve the total count of the files and the current index of the loop interaction? I need the total count, not the cumulative count to show the progress.
shell-script
add a comment |
The proper way to iterate over files in a directory in Bash is using "for loop" and glob as following:
for f in *.jpg; do
echo "- Processing file: $f"
done
But how can I retrieve the total count of the files and the current index of the loop interaction? I need the total count, not the cumulative count to show the progress.
shell-script
The proper way to iterate over files in a directory in Bash is using "for loop" and glob as following:
for f in *.jpg; do
echo "- Processing file: $f"
done
But how can I retrieve the total count of the files and the current index of the loop interaction? I need the total count, not the cumulative count to show the progress.
shell-script
shell-script
edited 4 hours ago
asked 5 hours ago
bman
13019
13019
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
I would store the list of files in an array, so that you don't have to read the file system twice, increasing performance and reducing potential race conditions. Then use another variable as the index.
files=(*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
i=$(( i + 1 ))
echo index $i
echo total $total
echo "- Processing file: $f"
done
Explanation
files=(*.jpg)
: store the glob into the array$files
total=${#files[@]}
: read the total into$total
i=0
: initialise$i
to 0.
i=$(( i + 1 ))
: add 1 to$i
each loop
This presumes that the "first" loop is 1. Depending on your opinion, you might want to start at 0 instead.
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:ls -1q *.jpg | wc -l
– bman
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsingls
is not great. Give me a minute and I'll edit.
– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
I would store the list of files in an array, so that you don't have to read the file system twice, increasing performance and reducing potential race conditions. Then use another variable as the index.
files=(*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
i=$(( i + 1 ))
echo index $i
echo total $total
echo "- Processing file: $f"
done
Explanation
files=(*.jpg)
: store the glob into the array$files
total=${#files[@]}
: read the total into$total
i=0
: initialise$i
to 0.
i=$(( i + 1 ))
: add 1 to$i
each loop
This presumes that the "first" loop is 1. Depending on your opinion, you might want to start at 0 instead.
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:ls -1q *.jpg | wc -l
– bman
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsingls
is not great. Give me a minute and I'll edit.
– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
add a comment |
I would store the list of files in an array, so that you don't have to read the file system twice, increasing performance and reducing potential race conditions. Then use another variable as the index.
files=(*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
i=$(( i + 1 ))
echo index $i
echo total $total
echo "- Processing file: $f"
done
Explanation
files=(*.jpg)
: store the glob into the array$files
total=${#files[@]}
: read the total into$total
i=0
: initialise$i
to 0.
i=$(( i + 1 ))
: add 1 to$i
each loop
This presumes that the "first" loop is 1. Depending on your opinion, you might want to start at 0 instead.
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:ls -1q *.jpg | wc -l
– bman
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsingls
is not great. Give me a minute and I'll edit.
– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
add a comment |
I would store the list of files in an array, so that you don't have to read the file system twice, increasing performance and reducing potential race conditions. Then use another variable as the index.
files=(*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
i=$(( i + 1 ))
echo index $i
echo total $total
echo "- Processing file: $f"
done
Explanation
files=(*.jpg)
: store the glob into the array$files
total=${#files[@]}
: read the total into$total
i=0
: initialise$i
to 0.
i=$(( i + 1 ))
: add 1 to$i
each loop
This presumes that the "first" loop is 1. Depending on your opinion, you might want to start at 0 instead.
I would store the list of files in an array, so that you don't have to read the file system twice, increasing performance and reducing potential race conditions. Then use another variable as the index.
files=(*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
i=$(( i + 1 ))
echo index $i
echo total $total
echo "- Processing file: $f"
done
Explanation
files=(*.jpg)
: store the glob into the array$files
total=${#files[@]}
: read the total into$total
i=0
: initialise$i
to 0.
i=$(( i + 1 ))
: add 1 to$i
each loop
This presumes that the "first" loop is 1. Depending on your opinion, you might want to start at 0 instead.
edited 4 hours ago
answered 5 hours ago
Sparhawk
9,33263991
9,33263991
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:ls -1q *.jpg | wc -l
– bman
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsingls
is not great. Give me a minute and I'll edit.
– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
add a comment |
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:ls -1q *.jpg | wc -l
– bman
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsingls
is not great. Give me a minute and I'll edit.
– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
I need to know the count while the for loop is running to show the progress, not at the end.
– bman
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
@bman I'm not sure what you mean. This will display the count during each loop, not at the end.
– Sparhawk
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:
ls -1q *.jpg | wc -l
– bman
4 hours ago
It displays the index, not the total count of files. I think I should use something like this for obtaining the count of files:
ls -1q *.jpg | wc -l
– bman
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsing
ls
is not great. Give me a minute and I'll edit.– Sparhawk
4 hours ago
@bman Ah got it. that might work generally, but (as you suggest in your question), parsing
ls
is not great. Give me a minute and I'll edit.– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
@bman Okay done.
– Sparhawk
4 hours ago
add a comment |
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