Shell – How to Count the Number of Lines of an Output

command linegrepshell

Let say I have the program:

Calculate.py

Is there a unix command-line that counts the number of lines outputted from my program, Calculate.py?

Best Answer

You can pipe the output in to wc. You can use the -l flag to count lines. Run the program normally and use a pipe to redirect to wc.

python Calculate.py | wc -l

Alternatively, you can redirect the output of your program to a file, say calc.out, and run wc on that file.

python Calculate.py > calc.out
wc -l calc.out

Related Solutions

Bash – Count Number of Lines of Output from Previous Program

You can use tee to split the output stream sending one copy to wc and the other copy to STDOUT like normal.

program | tee >(wc -l)

The >(cmd) is bash syntax which means run cmd and replace the >(cmd) bit with the path to (a named pipe connected to) that program's STDIN.

Shell – How to display the number of lines output by a command in real time

yourcommand | { I=0; while read; do printf "$((++I))\r"; done; echo ""; }

Or put the bracketed section in a shell script. Note that this only works if your shell actually supports the preincrement operator, like bash or ksh93 or zsh. Otherwise you'll have to increment $I and then print it (as in I=$((I+1));printf...). Also, if printf isn't a builtin with your shell (it's a builtin with current bash), you could use echo -ne or print -n instead for better performance. You just want to suppress the newline and have the \r interpreted as an escape character.

Best Answer

Related Solutions

Bash – Count Number of Lines of Output from Previous Program

Shell – How to display the number of lines output by a command in real time

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