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time arithmetic
Post 11059 by Perderabo on Wednesday 28th of November 2001 10:50:36 AM
11-28-2001
Looking at your code I couldn't believe that it would run at all. But I tried "echo aaa > bbb ccc" and sure enough I created a file called bbb with the contents "aaa ccc". I never knew you could inbed redirects in the middle of an argument list.
That's what you are doing with "if [ $a > $b ]". You should be creating an output file. The [ is just a normal unix command that expects it's last argument to be ]. In the early days of the bourne shell, it was a link to the test command and sat in /usr/bin. Later it became a built-in, but it still is a command. It never understood > as a comparison operator. There is a -gt but it only works on integers and will barf on your time format.
You don't want an integer compare, you want an ascii string compare. So switch to [[ which is a keyword rather than a command:
if [[ $a > $b ]]
should work fine.
And it's korn, not korne.
That's what you are doing with "if [ $a > $b ]". You should be creating an output file. The [ is just a normal unix command that expects it's last argument to be ]. In the early days of the bourne shell, it was a link to the test command and sat in /usr/bin. Later it became a built-in, but it still is a command. It never understood > as a comparison operator. There is a -gt but it only works on integers and will barf on your time format.
You don't want an integer compare, you want an ascii string compare. So switch to [[ which is a keyword rather than a command:
if [[ $a > $b ]]
should work fine.
And it's korn, not korne.
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LEARN ABOUT OPENDARWIN
script
SCRIPT(1) BSD General Commands Manual SCRIPT(1) NAME
script -- make typescript of terminal session SYNOPSIS
script [-a] [-k] [-q] [-t time] [file [command ...]] DESCRIPTION
The script utility makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of an interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1). If the argument file is given, script saves all dialogue in file. If no file name is given, the typescript is saved in the file typescript. If the argument command ... is given, script will run the specified command with an optional argument vector instead of an interactive shell. Options: -a Append the output to file or typescript, retaining the prior contents. -k Log keys sent to program as well as output. -q Run in quiet mode, omit the start and stop status messages. -t time Specify time interval between flushing script output file. A value of 0 causes script to flush for every character I/O event. The default interval is 30 seconds. The script ends when the forked shell (or command) exits (a control-D to exit the Bourne shell (sh(1)), and exit, logout or control-d (if ignoreeof is not set) for the C-shell, csh(1)). Certain interactive commands, such as vi(1), create garbage in the typescript file. The script utility works best with commands that do not manipulate the screen. The results are meant to emulate a hardcopy terminal, not an addressable one. ENVIRONMENT
The following environment variable is utilized by script: SHELL If the variable SHELL exists, the shell forked by script will be that shell. If SHELL is not set, the Bourne shell is assumed. (Most shells set this variable automatically). SEE ALSO
csh(1) (for the history mechanism). HISTORY
The script command appeared in 3.0BSD. BUGS
The script utility places everything in the log file, including linefeeds and backspaces. This is not what the naive user expects. It is not possible to specify a command without also naming the script file because of argument parsing compatibility issues. When running in -k mode, echo cancelling is far from ideal. The slave terminal mode is checked for ECHO mode to check when to avoid manual echo logging. This does not work when in a raw mode where the program being run is doing manual echo. BSD
June 6, 1993 BSD