grep output is not in stdout or stderr
I'm trying to find files that contain 'ash' and 'bun' with the following bash command:
grep --line-buffered -ril ash | xargs -d 'n' grep -il bun
Output from the first grep only (the names of files containing 'ash') appears as expected on the terminal screen, but nothing is being printed to the pipe. I verified this with:
grep --line-buffered -ril ash &> junk
junk is empty.
I have GNOME Terminal 3.6.2, GNU grep 2.16 and Ubuntu 14.04. The output from grep is coloured.
I'm aware of grep's buffering quirks but the output appears on separate lines, so I assume it's being flushed.
Anybody?
bash terminal grep stdout
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
add a comment |
I'm trying to find files that contain 'ash' and 'bun' with the following bash command:
grep --line-buffered -ril ash | xargs -d 'n' grep -il bun
Output from the first grep only (the names of files containing 'ash') appears as expected on the terminal screen, but nothing is being printed to the pipe. I verified this with:
grep --line-buffered -ril ash &> junk
junk is empty.
I have GNOME Terminal 3.6.2, GNU grep 2.16 and Ubuntu 14.04. The output from grep is coloured.
I'm aware of grep's buffering quirks but the output appears on separate lines, so I assume it's being flushed.
Anybody?
bash terminal grep stdout
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
Have you tried the simpler versiongrep -ril foo | xarg grep -il bar? Works for me. There is also this simpler syntax.
– xenoid
Feb 13 at 15:01
Thanks xenoid, some helpful ideas there (I'm not exactly sure what `cat -` is doing, but it looks promising). I've discovered that my issue remains a buffering issue. I thought --line-buffered would flush output to the pipe, but it doesn't seem to. The command works, it just doesn't print anything to the pipe until it's finished processing (even though the output is visible on the terminal).
– b1tr4t
Feb 13 at 19:40
You should also (and maybe, only ) force line-buffering on the second instance...
– xenoid
Feb 13 at 20:16
For some reason it's working more quickly now. Must be a system issue. --line-buffered on first, second or both doesn't seem to make any difference..
– b1tr4t
Feb 14 at 3:12
add a comment |
I'm trying to find files that contain 'ash' and 'bun' with the following bash command:
grep --line-buffered -ril ash | xargs -d 'n' grep -il bun
Output from the first grep only (the names of files containing 'ash') appears as expected on the terminal screen, but nothing is being printed to the pipe. I verified this with:
grep --line-buffered -ril ash &> junk
junk is empty.
I have GNOME Terminal 3.6.2, GNU grep 2.16 and Ubuntu 14.04. The output from grep is coloured.
I'm aware of grep's buffering quirks but the output appears on separate lines, so I assume it's being flushed.
Anybody?
bash terminal grep stdout
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
I'm trying to find files that contain 'ash' and 'bun' with the following bash command:
grep --line-buffered -ril ash | xargs -d 'n' grep -il bun
Output from the first grep only (the names of files containing 'ash') appears as expected on the terminal screen, but nothing is being printed to the pipe. I verified this with:
grep --line-buffered -ril ash &> junk
junk is empty.
I have GNOME Terminal 3.6.2, GNU grep 2.16 and Ubuntu 14.04. The output from grep is coloured.
I'm aware of grep's buffering quirks but the output appears on separate lines, so I assume it's being flushed.
Anybody?
bash terminal grep stdout
bash terminal grep stdout
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
asked Feb 13 at 10:27
b1tr4tb1tr4t
1
1
Have you tried the simpler versiongrep -ril foo | xarg grep -il bar? Works for me. There is also this simpler syntax.
– xenoid
Feb 13 at 15:01
Thanks xenoid, some helpful ideas there (I'm not exactly sure what `cat -` is doing, but it looks promising). I've discovered that my issue remains a buffering issue. I thought --line-buffered would flush output to the pipe, but it doesn't seem to. The command works, it just doesn't print anything to the pipe until it's finished processing (even though the output is visible on the terminal).
– b1tr4t
Feb 13 at 19:40
You should also (and maybe, only ) force line-buffering on the second instance...
– xenoid
Feb 13 at 20:16
For some reason it's working more quickly now. Must be a system issue. --line-buffered on first, second or both doesn't seem to make any difference..
– b1tr4t
Feb 14 at 3:12
add a comment |
Have you tried the simpler versiongrep -ril foo | xarg grep -il bar? Works for me. There is also this simpler syntax.
– xenoid
Feb 13 at 15:01
Thanks xenoid, some helpful ideas there (I'm not exactly sure what `cat -` is doing, but it looks promising). I've discovered that my issue remains a buffering issue. I thought --line-buffered would flush output to the pipe, but it doesn't seem to. The command works, it just doesn't print anything to the pipe until it's finished processing (even though the output is visible on the terminal).
– b1tr4t
Feb 13 at 19:40
You should also (and maybe, only ) force line-buffering on the second instance...
– xenoid
Feb 13 at 20:16
For some reason it's working more quickly now. Must be a system issue. --line-buffered on first, second or both doesn't seem to make any difference..
– b1tr4t
Feb 14 at 3:12
Have you tried the simpler version
grep -ril foo | xarg grep -il bar? Works for me. There is also this simpler syntax.– xenoid
Feb 13 at 15:01
Have you tried the simpler version
grep -ril foo | xarg grep -il bar? Works for me. There is also this simpler syntax.– xenoid
Feb 13 at 15:01
Thanks xenoid, some helpful ideas there (I'm not exactly sure what `cat -` is doing, but it looks promising). I've discovered that my issue remains a buffering issue. I thought --line-buffered would flush output to the pipe, but it doesn't seem to. The command works, it just doesn't print anything to the pipe until it's finished processing (even though the output is visible on the terminal).
– b1tr4t
Feb 13 at 19:40
Thanks xenoid, some helpful ideas there (I'm not exactly sure what `cat -` is doing, but it looks promising). I've discovered that my issue remains a buffering issue. I thought --line-buffered would flush output to the pipe, but it doesn't seem to. The command works, it just doesn't print anything to the pipe until it's finished processing (even though the output is visible on the terminal).
– b1tr4t
Feb 13 at 19:40
You should also (and maybe, only ) force line-buffering on the second instance...
– xenoid
Feb 13 at 20:16
You should also (and maybe, only ) force line-buffering on the second instance...
– xenoid
Feb 13 at 20:16
For some reason it's working more quickly now. Must be a system issue. --line-buffered on first, second or both doesn't seem to make any difference..
– b1tr4t
Feb 14 at 3:12
For some reason it's working more quickly now. Must be a system issue. --line-buffered on first, second or both doesn't seem to make any difference..
– b1tr4t
Feb 14 at 3:12
add a comment |
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Have you tried the simpler version
grep -ril foo | xarg grep -il bar? Works for me. There is also this simpler syntax.– xenoid
Feb 13 at 15:01
Thanks xenoid, some helpful ideas there (I'm not exactly sure what `cat -` is doing, but it looks promising). I've discovered that my issue remains a buffering issue. I thought --line-buffered would flush output to the pipe, but it doesn't seem to. The command works, it just doesn't print anything to the pipe until it's finished processing (even though the output is visible on the terminal).
– b1tr4t
Feb 13 at 19:40
You should also (and maybe, only ) force line-buffering on the second instance...
– xenoid
Feb 13 at 20:16
For some reason it's working more quickly now. Must be a system issue. --line-buffered on first, second or both doesn't seem to make any difference..
– b1tr4t
Feb 14 at 3:12