File Monitoring with “tail” Command:

tail has a special command line option -f (follow) that allows a file to be monitored. Instead of just displaying the last few lines and exiting, tail keeps displaying the latest lines in the specified file, in real-time. This is particularly useful for monitoring log files.

username@neser:rhel:fen3:$RUN$ tail -f log.icoFoam 
DILUPBiCG:  Solving for Ux, Initial residual = 1.89493e-07, Final residual = 1.89493e-07, 
No Iterations 0
DILUPBiCG:  Solving for Uy, Initial residual = 4.14522e-07, Final residual = 4.14522e-07,
No Iterations 0
DICPCG:  Solving for p, Initial residual = 1.06665e-06, Final residual = 3.39604e-07, 
No Iterations 1
time step continuity errors : sum local = 5.25344e-09, global = -9.50761e-19,
cumulative = 8.05678e-18
DICPCG:  Solving for p, Initial residual = 5.36118e-07, Final residual = 5.36118e-07,
No Iterations 0
time step continuity errors : sum local = 6.86432e-09, global = 4.62063e-19,
cumulative = 8.51884e-18
ExecutionTime = 0.19 s  ClockTime = 0 s
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