Thank you Chet, In that case, how do I compile my own bash with specific version of readline? I can not install readline to system but I can compile both in my home directory.
Thanks Manish. On 2/4/20 10:07 AM, Chet Ramey wrote: > On 2/3/20 3:26 PM, Manish Patel wrote: > >> Bash Version: 4.4 >> Patch Level: 20 >> Release Status: release >> >> Description: >> Print/echo is lost when generated from a function in >> COMMAND_PROMPT and placed in background in subshell. >> >> I have embedded some git information in my command prompt. >> However, due to large git data, it takes some time to calculate it all. >> So I have placed >> the git processing in the background function, which I call from >> COMMAND_PROMPT. > Readline assumes two things: it starts with the cursor in column 0, and > it is the only thing writing to the screen during redisplay, so it always > knows where the cursor is and can make redisplay decisions accordingly. > Your writing to the screen from a background process violates one or both > of these, so all bets are off. It may be the case that readline decides to > redisplay by moving to column 0, redrawing the prompt, moving the cursor, > and redrawing the changed portions of the line,in which case whatever your > process writes at the beginning of the line gets overwritten. It may be the > case that writing to the screen moves the cursor forward so readline > doesn't move the cursor to the right place or wrap correctly. > > There are no guarantees that anything a background process writes to the > screen will be preserved, or that writing to the screen and moving the > physical cursor will not interfere with readline's redisplay. > > Chet >
