...
| Expand | |||||
|---|---|---|---|---|---|
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Add a count to the unique run lines then sort on it numerically, in reverse order. The 1st line will then be the job with the most lines (jobs).
|
reading file lines
The read function can be used to read input one line at a time. While the full details of read are complicated (see https://unix.stackexchange.com/questions/209123/understanding-ifs-read-r-line) this read-a-line-at-a-time idiom works nicely.
| Code Block | ||
|---|---|---|
| ||
lineNo=1
while IFS= read line; do
echo "Line $lineNo: '$line'"
lineNo=$(( lineNo + 1 ))
done < sampleinfo.txt |
- The IFS= clears all of read's default input field separators (whitespace).
- This is needed so that read will set the line variable to exactly the contents of the input line, and not strip leading whitespace from it.
- Note the odd syntax for incrementing the line number variable.
field delimiter issues
Always be aware of the default field delimiter for the various bash utilities, and how to change them:
| utility | default delimiter | how to change | example |
|---|---|---|---|
| cut | tab | -d or --delimiter option | cut -d ':' -f 1 /etc/passwd |
| sort | whitespace (one ore more spaces or tabs) | -t or --field-separator option | sort -t ':' -k1,1 /etc/passwd |
| awk | whitespace (one ore more spaces or tabs) for both input and output |
|
cat sampleinfo.txt | awk -F "\t" '{ print $1,$3 }' |
| join | one or more spaces | -t option | |
| perl | whitespace (one ore more spaces or tabs) when auto-splitting input with -a | -F'/<pattern>/' option | cat sampleinfo.txt | perl -F'/\t/' -ane 'print "$F[0]\t$F[2]\n";' |
| read | whitespace (one ore more spaces or tabs | IFS= option | see example above |