shell脚本编程入门教程(2)

[search@h1 logs]$ man less 
LESS(1)  LESS(1) 
 
NAME 
       less - opposite of more 
 
SYNOPSIS 
       less -? 
       less --help 
       less -V 
       less --version 
       less [-[+]aBcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~] 
            [-b space] [-h lines] [-j line] [-k keyfile] 
            [-{oO} logfile] [-p pattern] [-P prompt] [-t tag] 
            [-T tagsfile] [-x tab,...] [-y lines] [-[z] lines] 
            [-# shift] [+[+]cmd] [--] [filename]... 
       (See the OPTIONS section for alternate option syntax with long option names.) 
 
DESCRIPTION 
       Less  is  a  program similar to more (1), but which allows backward movement in the file as well as forward movement.  Also, less does not have to read 
       the entire input file before starting, so with large input files it starts up faster than text editors like vi (1).  Less uses termcap (or terminfo  on 
       some  systems),  so  it can run on a variety of terminals.  There is even limited support for hardcopy terminals.  (On a hardcopy terminal, lines which 
       should be printed at the top of the screen are prefixed with a caret.) 
 
       Commands are based on both more and vi.  Commands may be preceded by a decimal number, called N in the descriptions below.  The number is used by  some 
       commands, as indicated. 
 
COMMANDS 
       In  the  following  descriptions, ^X means control-X.  ESC stands for the ESCAPE key; for example ESC-v means the two character sequence "ESCAPE", then 
       "v". 
 
       h or H Help: display a summary of these commands.  If you forget all the other commands, remember this one. 
 
       SPACE or ^V or f or ^F 
              Scroll forward N lines, default one window (see option -z below).  If N is more than the screen size, only the  final  screenful  is  displayed. 
              Warning: some systems use ^V as a special literalization character. 
 
       z      Like SPACE, but if N is specified, it becomes the new window size. 
 
       ESC-SPACE 
              Like SPACE, but scrolls a full screenful, even if it reaches end-of-file in the process. 
 
       RETURN or ^N or e or ^E or j or ^J 
              Scroll forward N lines, default 1.  The entire N lines are displayed, even if N is more than the screen size. 
 
       d or ^D 
              Scroll forward N lines, default one half of the screen size.  If N is specified, it becomes the new default for subsequent d and u commands. 
 
       b or ^B or ESC-v 
              Scroll backward N lines, default one window (see option -z below).  If N is more than the screen size, only the final screenful is displayed. 
 
       w      Like ESC-v, but if N is specified, it becomes the new window size. 
 
       y or ^Y or ^P or k or ^K 
              Scroll  backward N lines, default 1.  The entire N lines are displayed, even if N is more than the screen size.  Warning: some systems use ^Y as 
    
 

[search@h1 logs]$ man tail 
TAIL(1)                          User Commands                         TAIL(1) 
 
NAME 
       tail - output the last part of files 
 
SYNOPSIS 
       tail [OPTION]... [FILE]... 
 
DESCRIPTION 
       Print  the  last 10 lines of each FILE to standard output.  With more than one FILE, precede each with a header giving the file name.  With no FILE, or 
       when FILE is -, read standard input. 
 
       Mandatory arguments to long options are mandatory for short options too. 
 
       -c, --bytes=K 
              output the last K bytes; alternatively, use -c +K to output bytes starting with the Kth of each file 
 
       -f, --follow[={name|descriptor}] 
              output appended data as the file grows; -f, --follow, and --follow=descriptor are equivalent 
 
       -F     same as --follow=name --retry 
 
       -n, --lines=K 
              output the last K lines, instead of the last 10; or use -n +K to output lines starting with the Kth 
 
       --max-unchanged-stats=N 
              with --follow=name, reopen a FILE which has not changed size after N (default 5) iterations to see if it has been unlinked or renamed  (this  is 
              the usual case of rotated log files).  With inotify, this option is rarely useful. 
 
       --pid=PID 
              with -f, terminate after process ID, PID dies 
 
       -q, --quiet, --silent 
              never output headers giving file names 
 
       --retry 
              keep trying to open a file even when it is or becomes inaccessible; useful when following by name, i.e., with --follow=name 
 
       -s, --sleep-interval=N 
              with -f, sleep for approximately N seconds (default 1.0) between iterations. 
 
              With inotify and --pid=P, check process P at least once every N seconds. 
 
       -v, --verbose 
              always output headers giving file names 
 
       --help display this help and exit 
 
       --version 
              output version information and exit 
 
       If  the  first  character of K (the number of bytes or lines) is a ‘+’, print beginning with the Kth item from the start of each file, otherwise, print 
       the last K items in the file.  K may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G  1024*1024*1024, 
       and so on for T, P, E, Z, Y. 
 
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