A lab I sometimes do computer work for asked for a mechanism to account how long each user spends logged in on some *nix (Linux and ancient Solaris) boxes. I don’t know of a “proper” solution, so I did things the UNIX way: I wrote a stupid little awk script that parses the output of last -R to get a minute total. This isn’t a terribly clean or safe script, but it does “just enough” input sanitizing, and seems to work. Some (Linux) boxes I have access to appear to clear\/archive\/rotate wtmp on boot, so it doesn’t help on those.
\nDoes anyone know of a better way to do this? Is there some utility I’m forgetting? Is this script dangerous in some way I’m not thinking of? Script follows:<\/p>\n
#!\/bin\/sh\nlast -R | \nawk '\n{\n\tuser=$1;\n\tuselength=$9;\n\t\n#\tCheck line format\n\tif (NF != 9) {\n\tprint \"Line \" NR \" discarded, \" NF \" entries. (Reboot messages, etc.)\"\n\t}\n\telse if( $NF == \"in\"){\n\tprint \"Line \" NR \" discarded, still logged in.\"\n\t}\n\telse{\n\t\n\tlogins[user]++;\n# These times are (Days+Hours:Minutes)\n\tparsedtime=0;\n\tgsub(\"[()]\",\"\",uselength);\n\tsplit(uselength, sptime, \"[+:]\");\n\tparsedtime+=sptime[1]*24*60;\n\tparsedtime+=sptime[2]*60;\n\tparsedtime+=sptime[3];\n\tlogintime[user]+=parsedtime;\n\t}\n}\n\t\nEND {\n\tfor (i in logins) {\n\t\tprint i \" Logged in \" logins[i] \" times, for a total of \" logintime[i] \" minutes\";\n\t}\n}'\n<\/pre>\n","protected":false},"excerpt":{"rendered":"A lab I sometimes do computer work for asked for a mechanism to account how long each user spends logged in on some *nix (Linux and ancient Solaris) boxes. I don’t know of a “proper” solution, so I did things … Continue reading