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External Command Reference SKsh A ksh-like Shell for the Amiga Version 1.4 (Copyright) 1989, 1990 Steve Koren March 19, 1990 Table of Contents Introduction......................................3 cmp...............................................4 cp................................................5 crc...............................................6 du................................................7 fgrep.............................................8 grep..............................................10 head..............................................12 join..............................................13 strings...........................................14 srun..............................................15 tail..............................................16 tee...............................................17 view..............................................18 wc................................................19 window............................................20 xd................................................21 SKsh Amiga Shell Page 2 External Cmd Reference Introduction This reference manual describes each SKsh external command in a concise manner. Each page contains the following information: Name: The name of the command. Type: Always External Command for this document; may be something else in the reference manual. Default: Default parameters, if applicable. Usage: Command syntax Range: Legal values for variables or parameters About: Text describing the command, variable, etc. Example: A brief example usage. See Also: Other related commands, variables, etc. When reading the command syntax, anything in square brackets is optional. Anything followed by three dots can be repeated any number of times. A vertical bar is used to separate option where one or the other, but not both, can be used. In general, 'command -a -b' is equilivant to 'command -ab'. All external commands were re-written in SKsh 1.4 to be much smaller and faster than their earlier counterparts. SKsh Amiga Shell Page 3 External Cmd Reference ________________________________________________________________ Name: cmp Type: External Command Default: n/a Usage: cmp [ -s ] file1 file2 Range: n/a About: cmp compares two files for equality. It can be used on binary as well as textual data. cmp is fast in that if the files are not the same size, it won't even bother comparing the contents of the files. cmp normally outputs a message that indicates whether the files are the same, different, or one is shorter than the other. If the -s option is used, compare does not output this information, but simply returns a zero exit status if the files were the same, or non-zero if they were not. Example: if cmp -s file1 file2 then echo 'file1 is the same as file2' else echo 'file1 is different than file2' fi See Also: ________________________________________________________________ SKsh Amiga Shell Page 4 External Cmd Reference ________________________________________________________________ Name: cp Type: Builtin Default: n/a Usage: cp [ -nuv ] file { file | dir } cp [ -nruv ] { file | dir } ... dir Range: n/a About: cp copies files from one place to another, optionally renaming them in the process. If the destination is a directory, the files have the same name in the destination directory. If more than one file is copied, the destination must be either a directory or nonexistant. If it is nonexistant, it is created as a directory. The -r flag causes cp to perform a recursive copy. The -v flag prints the name of each file as it is copied. The -n flag causes cp NOT to duplicate file modification times and protection flags on the destination files. If you wish to make this the default behavior, use this alias: alias cp='$(which cp) -n' cp will reset the AmigaDos archive bit whether or not the -v flag is used. The -u flag causes cp to operate in "update" mode; only files with a newer timestamp than their associated destination are copied. Example: cp my_file1 m_file2 my_file3 my_directory Warnings: The -c (clone) flag was obsoleted in SKsh 1.4. It is still accepted for backward compatibility; however, it is ignored. Use the -n option to turn off the clone behaviour. The cp command was changed to an external binary in SKsh 1.4. It used to be a builtin. See Also: mv ________________________________________________________________ SKsh Amiga Shell Page 5 External Cmd Reference ________________________________________________________________ Name: crc Type: External Command Default: n/a Usage: crc file1 file2 Range: n/a About: crc generates several 32 bit values which are computed from a file's contents. These values can be used to check the integrity of files which are transfered over a medium of questionable reliability (such as phone lines). Example: crc a_file another_file See Also: ________________________________________________________________ SKsh Amiga Shell Page 6 External Cmd Reference ________________________________________________________________ Name: du Type: External Command Default: n/a Usage: du [ -dkst ] dir ... Range: n/a About: du prints disk usage information for a set of directories. For each directory listed on the command line, the subtree rooted at that point is searched in a depth-first manner. du adds all the file sizes, and for each directory, prints 1) the directory name, 2) the total disk usage for files in this directory, and 3) the total disk usage for the subtree rooted at this directory. The following options are available: -k Print disk usage in 1024 byte kilobytes instead of the default bytes. -s Summary mode; print disk usage only for root directories listed on the command line. This option omits the display for any sub-directories, but still must examine the entire directory subtree to find the total disk usage. -d Omit the first disk usage number (the total for this directory only). -t Omit the second disk usage number (the total for the subtree rooted at this directory). If both -t and -d are used, only directory names are printed. Example: du devs: ram: du -s devs: Warnings: The -k option rounds to the nearest kilobyte. For example, a 1023 byte file is printed as 1K, and a 511 byte file is printed as 0K. This means that the rooted subtree disk usage count may not be the sum of the directory disk usage counts for all subdirectories. See Also: info ________________________________________________________________ SKsh Amiga Shell Page 7 External Cmd Reference ________________________________________________________________ Name: fgrep Type: External Command Default: n/a Usage: fgrep -[vxcilns] [-f pfile] [-e] pattern [ file ... ] Range: n/a About: fgrep provides a fast way to search for text patterns in a set of files. It is similar to, although more limited but faster than, grep. fgrep searches for the indicated pattern in the indicated set of files, if present, or the standard input, if not. An fgrep pattern is extremely limited; it can be either a string constant or a set of string constants separated by percent signs. For example, these are valid fgrep statements: fgrep my_routine *.c fgrep 'this%or%that' my_file my_other_file In the second example, fgrep searches for lines containing any of the three strings. There are a large number of options availble which modify the actions of fgrep: -c Print only a count of matching lines for each file. If the 'v' option is used with the 'c' option, a count of non-matching lines is printed. -e Use the next argument as the pattern. This is useful to search for patterns beginning with a dash. -f Use the next argument as a file which contains a newline separated list of values. This file is read and used in place of the command line pattern. For example, the following two examples are equivalent: fgrep 'foo%bar' myfile echo "foo" >temp; echo "bar" >>temp fgrep -f temp myfile SKsh Amiga Shell Page 8 External Cmd Reference -i Ignore case in the search. Normally, fgrep is case sensitive. -l Print only the names of files which containg the given pattern. This is fast; if fgrep finds the pattern anywhere in the file, it will stop looking and proceed to the next file. This can save time for large files where the task is to discover which files contain the given pattern. -n Print the line number before each matching line. -s Print nothing. Return an exit code of 0 (true) if any file contained the pattern, or 1 (false) if no files contained the pattern. -v Invert the search. Lines which do not contain the pattern are printed. -x Lines must match the pattern exactly, not simply contain it. Example: if grep -s my_pattern my_file then echo 'my_file contains my_pattern' fi Warnings: Patterns which contain '%', spaces, or other special characters should be quoted to avoid being interpreted by the shell. The '%' character is used to separate strings instead of a newline in Un*x, as there is a problem in AmigaDos passing parameters containing newlines to external commands. See Also: grep ________________________________________________________________ SKsh Amiga Shell Page 9 External Cmd Reference ________________________________________________________________ Name: grep Type: External Command Default: n/a Usage: grep -[vxcilns] [-f pfile] [-e] pattern [ file ... ] Range: n/a About: grep provides a way to search for text patterns in a set of files. It is similar to, although more powerful but slower than, fgrep. grep searches for the indicated pattern in the indicated set of files, if present, or the standard input, if not. A grep pattern is a limited regular expression. An explaination of regular expressions is beyond the scope of this document; however, it should be noted that although they appear similar to wildcards, they are much different (and more powerful). There are a large number of options availble which modify the actions of grep: -c Print only a count of matching lines for each file. If the 'v' option is used with the 'c' option, a count of non-matching lines is printed. -e Use the next argument as the pattern. This is useful to search for patterns beginning with a dash. -f Use the next argument as a file which contains a one-line regular expression. There can only be one regular expression in this version of grep, so this option is currently of limited use. However, if grep is extended to permit multiple expressions, the 'f' option will become more useful. -i Ignore case in the search. Normally, grep is case sensitive. -l Print only the names of files which containg the given pattern. This is fast; if grep finds the pattern anywhere in the file, it will stop looking and proceed to the next file. This can save time for large files SKsh Amiga Shell Page 10 External Cmd Reference where the task is to discover which files contain the given pattern. -n Print the line number before each matching line. -s Print nothing. Return an exit code of 0 (true) if any file contained the regular expression, or 1 (false) otherwise. -v Invert the search. Lines which do not contain the regular expression are printed. -x The expression must be found at the beginning of a line. Example: if grep -s my_pattern my_file then echo 'my_file contains my_pattern' fi Warnings: Patterns which contain '*', '.', spaces, or other special characters should be quoted to avoid being interpreted by the shell. Be wary of the difference in the 'x' option between fgrep and grep. fgrep often more useful than grep because of its greater speed and smaller size. This is most noticable on fast devices such as ram or hard disks. See Also: fgrep ________________________________________________________________ SKsh Amiga Shell Page 11 External Cmd Reference ________________________________________________________________ Name: head Type: External Command Default: num = 10 Usage: head [ -num ] [ file ... ] Range: 0 <= num About: head prints the first num lines of each named file, or the standard input if no files are indicated. If num is not explicitly set, it has a default value of 10. Example: head -5 my_file.c my_other_file.c See Also: tail ________________________________________________________________ SKsh Amiga Shell Page 12 External Cmd Reference ________________________________________________________________ Name: join Type: External Command Default: n/a Usage: join [ -a ] source1 [ source2 ... ] destination Range: n/a About: The join command concatinates binary or ascii data from multiple files into a single file, optionally appending the data to the destination file if the -a flag is set. The destination file is the last one given. Example: join file1 file2 dest_file See Also: ________________________________________________________________ SKsh Amiga Shell Page 13 External Cmd Reference ________________________________________________________________ Name: strings Type: External Command Default: num = 6 Usage: strings [ -num ] [ file ... ] Range: 0 <= num About: strings searches the named files for strings of at least num consecutive printable characters. If found, it prints them. If num is not set, it defaults to 6. Example: strings -10 my_file.o binary_file See Also: ________________________________________________________________ SKsh Amiga Shell Page 14 External Cmd Reference ________________________________________________________________ Name: srun Type: External Command Default: stk = 4000 pri = 0 Usage: srun [ -i file ] [ -o file ] [ -s stk ] [ -p pri ] program [ args ] Range: 4000 <= stk -31 <= pri <= 31 About: srun was created to overcome certain deficiencies in the AmigaDos run command. srun is most useful in scripts or functions, although it can also be used from the command line. It allows you to specify an input file, output file, stack size, and priority for a command which is run in the background. Standard input and output cannot be re-directed with the AmigaDos run command. The srun command is very useful in functions such as the one given below (very much simplified from one given in the Stuff.sksh file). Example: function zmore { srun -o pipe:tmp $(which zoo) -print "$1" "$2" more pipe:tmp } See Also: run ________________________________________________________________ SKsh Amiga Shell Page 15 External Cmd Reference ________________________________________________________________ Name: tail Type: External Command Default: num = 10, '-' option Usage: tail [ -num | +num ] [ file ... ] Range: 0 <= num <= 32000 About: tail prints the last num lines of each named file, or the standard input if no files are named. If a '+' precedes num instead of a '-', tail instead skips num lines and prints the rest of the file. In SKsh 1.4, the algorithm used by tail was changed. If run on a file, it will now seek to the end of the file and read backwards until it encounters the proper line. This means that running tail on a large file is now nearly instantaneous; previously, it would read in the entire file. Example: tail -15 my_file.c my_other_file.c See Also: head ________________________________________________________________ SKsh Amiga Shell Page 16 External Cmd Reference ________________________________________________________________ Name: tee Type: External Command Default: n/a Usage: tee [ -a ] [ file ... ] Range: less than 32 files About: tee copies its standard input to its standard output, and also to any named files. The old contents of the files are overwritten unless the append (-a) flag is used. With no arguments, tee simply copies its input to its output. Example: fgrep foo my_file | tee save_foo | wc -c See Also: _______________________________________________________________ SKsh Amiga Shell Page 17 External Cmd Reference ________________________________________________________________ Name: view Type: External Command Default: n/a Usage: see View.doc Range: n/a About: view is a command which allows other commands to be called based on the type of a given file. See the View.doc manual for a detail description of this command. Example: See Also: ________________________________________________________________ SKsh Amiga Shell Page 18 External Cmd Reference ________________________________________________________________ Name: wc Type: External Command Default: n/a Usage: wc [ -hcwlqt ] [ file ... ] Range: n/a About: wc is a utility which counts characters, words, or lines in a given series of files (or the standard input, if no files are indicated). It normally produces information on all three counts, preceded by a title for each column. If the c, w, or l flags are set, only information on characters, words, or lines is printed. (These can be combined; for example 'wc -cl'). If the q flag is set, wc does its work quietly; that is, it leaves out titles and file names, only reporting the actual counts. The t flag can be used to obtain a total at the end, and the h flag prints a helpful usage message. Example: if [ $(wc -lq my_file) -lt 10 ] then echo "There must be at least 10 lines" fi See Also: ________________________________________________________________ SKsh Amiga Shell Page 19 External Cmd Reference ________________________________________________________________ Name: window Type: External Command Default: n/a Usage: window [ -back ] [ -front ] [ -title ] [ -pos [x,y] ] [ -size [x,y] ] [ -scrsize ] [ -wmouse ] [ -smouse ] Range: n/a About: window is a command which allows parameters of the current shell window to be modified or examined. The -back and -front flags cause the window to be sent to the back or front. The -title flag causes the current window title to be printed. The -pos flag with no following parameters can be used to find the current x and y positions of the window. With a comma separated set of numbers, it moves the window to that position if possible. Similarly, the -size parameter either reports the size of the current window in pixels, or resizes the window to that size if possible. The -scrsize flag reports the current size of the screen containing this window, and the -smouse and - wmouse flags report the cursor position relative to the screen or window. With no parameters, the window command prints a helpful usage message. Note that this usage message contains one additional option which can be included after the -title flag to change the window title to a set value. However, this is not actually permitted by AmigaDos, and although it works now, it may cause problems, and its use is not recommended. Use at your own risk. Example: # move window to back and upper left hand corner window -back -pos 0,0 See Also: ________________________________________________________________ SKsh Amiga Shell Page 20 External Cmd Reference ________________________________________________________________ Name: xd Type: External Command Default: n/a Usage: xd [ file ... ] Range: n/a About: xd (hex dump) prints a hexadecimal dump of each named file, or the standard input if no files are named. It prints the hex address of the current offset as 8 digits, then a hex dump of 16 bytes separated into groups of 2 bytes, then an ASCII representation of the 16 bytes, or '.' if the byte is not a printable character. Example: xd any_old_file See Also: ________________________________________________________________ SKsh Amiga Shell Page 21 External Cmd Reference