projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 8594a067 BJ |
1 | .TH DMESG 1M |
| 2 | .SH NAME | |
| 3 | dmesg \- collect system diagnostic messages to form error log | |
| 4 | .SH SYNOPSIS | |
| 5 | .B /etc/dmesg | |
| 6 | [ \- ] | |
| 7 | .SH DESCRIPTION | |
| 8 | .I Dmesg | |
| 9 | looks in a system buffer for recently printed diagnostic messages | |
| 10 | and prints them on the standard output. | |
| 11 | The messages are those printed by the system when device (hardware) errors occur | |
| 12 | and (occasionally) when system tables overflow non-fatally. | |
| 13 | If the | |
| 14 | .B \- | |
| 15 | flag is given, then | |
| 16 | .I dmesg | |
| 17 | computes (incrementally) the new messages since the last time it | |
| 18 | was run and places these on the standard output. | |
| 19 | This is typically used with | |
| 20 | .IR cron (8) | |
| 21 | to produce the error log | |
| 22 | .I /usr/adm/messages | |
| 23 | by running the command | |
| 24 | .IP | |
| 25 | /etc/dmesg \- >> /usr/adm/messages | |
| 26 | .LP | |
| 27 | every 10 minutes. | |
| 28 | .SH FILES | |
| 29 | .ta 2i | |
| 30 | /usr/adm/messages error log (conventional location) | |
| 31 | .br | |
| 32 | /usr/adm/msgbuf scratch file for memory of \- option | |
| 33 | .SH BUGS | |
| 34 | The system error message buffer is of small finite size. As | |
| 35 | .I dmesg | |
| 36 | is run only every few minutes, not all error messages | |
| 37 | are guaranteed to be logged. This can be construed as a blessing rather | |
| 38 | than a curse. | |
| 39 | .PP | |
| 40 | Error diagnostics generated immediately before a system crash will | |
| 41 | never get logged. |