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Shell Programming and Scripting
Troubles with pipes, fork, and dup2
Post 302873041 by dano88 on Monday 11th of November 2013 04:04:38 AM
11-11-2013
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LEARN ABOUT OSF1
log
log(8) System Manager's Manual log(8) NAME
log - Records input and output from a program SYNOPSIS
/usr/sbin/log <logfile> <command> OPERANDS
The file in which to record the interaction being logged. The command to execute. DESCRIPTION
The log program runs <command> and logs the input to and output from <command> to the <logfile> file. Input and output are logged until <command> exits, the log program exits, and the exit status of <command> is returned. The log program is used by the system installation procedure and the it(8) command to create the /var/adm/smlogs/install.log and /var/adm/smlogs/it.log installation log files. RESTRICTIONS
Because the log program is used in the installation standalone environment, program size was the greatest concern in its implementation. The log program does not search for the PATH variable to locate <command> and error messages are terse. The log program causes <command> to take standard input from and write standard output and standard error to UNIX pipes. Some commands will not be able to operate in this environment; therefore, it is suggested that you use the script(1) command instead. UNIX shells will not issue prompts when run from log unless the shell is started with an explicit interactive switch (-i for most shells). For example, log foo.tmp /sbin/sh -i In the previous example, foo.tmp is the name of <logfile>. The log program intercepts end-of-file (usually Ctrl/d). Therefore programs which normally receive end-of-file as an exit command must exit by some other means. ERRORS
Log open error Explanation: The log program was unable to open <logfile>. Verify that the directory exists and that ownerships and permissions are set correctly. Exec Error Explanation: The log program was unable to execute <command>. Verify that you specified a full pathname for <command> and that <command> is an exe- cutable file. Fork Error Explanation: The log program was unable to create one of the processes it requires to log data. SEE ALSO
Commands: it(8), script(1) log(8)