Read user input inside a loop

Question

I am having a bash script which is something like following   cat filename   while read line do     read input      echo  input  done   but this is clearly not giving me the right output as when I do read in the while loop it tries to read from the file filename because of the possible I O redirection   Any other way of doing the same

User · Answer

Try to change the loop like this   for line in   cat filename   do     read input     echo  input  done   Unit test   for line in   cat  etc passwd   do     read input     echo  input      echo    line   done

User · Answer

echo  Enter the Programs you want to run    gt    PROGRAM LIST  while read PROGRAM ENTRY do    if     -s   PROGRAM ENTRY       then       echo   PROGRAM ENTRY   gt  gt    PROGRAM LIST     else       break    fi done

User · Answer

You can redirect the regular stdin through unit 3 to keep the get it inside the pipeline     cat notify-finished   while read line  do     read -u 3 input     echo   input  done    3 lt  amp 0   BTW  if you really are using cat this way  replace it with a redirect and things become even easier   while read line  do     read -u 3 input     echo   input  done 3 lt  amp 0  lt notify-finished   Or  you can swap stdin and unit 3 in that version -- read the file with unit 3  and just leave stdin alone   while read line  lt  amp 3  do       read  amp  use stdin normally inside the loop     read input     echo   input  done 3 lt notify-finished

User · Answer

I have found this parameter -u with read    -u 1  means  read from stdin    while read -r newline  do       i         read -u 1 -p  Doing  i  th file  called  newline  Write your answer and press Enter       echo  Processing  newline with  REPLY    united input from two different read commands  done  lt  lt  lt    ls

User · Answer

It looks like you read twice  the read inside the while loop is not needed  Also  you don t need to invoke the cat command   while read input do     echo  input done  lt  filename

User · Answer

Read from the controlling terminal device   read input  lt  dev tty   more info  http   compgroups net comp unix shell Fixing-stdin-inside-a-redirected-loop

[bash] Read user input inside a loop

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