Network Computingwww.networkcomputing.com

Listing 1: A make file dependency generator lists the header files required by each object-file target.

A. Listing of the Perl script:

1   #!/usr/bin/perl
2   # @(#) makedepend  List make target dependencies
3   # Author: Dale Mensch, July 1993
4   # Modified by: Becca Thomas, January 1994
5  
6   # CONFIGURATION PARAMETERS:
7  
8   # Using GNU make?
9   $have_gmake = 0;                        # 0 = No, 1 = Yes
10  
11  # Choose the source-file suffix:
12  $source_suffix = '.c';                  # Possibilities: .C, .cpp, .cc
13  
14  # Choose the object-file suffix:
15  $object_suffix = '.o';                  # Another possibility: .xo
16  
17  # List directories containing header files that don't change:
18  $ignore_include_dirs = '/usr/include';  # Don't need to list these
19  
20  # Location of standard header files:
21  $add_include_dirs = '-I/usr/include';   # If not included automatically
22  
23  # Command that runs preprocessor, includes headers, excludes comments:
24  $cpp_cmd = 'cc -E';
25  
26  # MAIN PROGRAM:
27  
28  # Check correct command line usage:
29  die "Usage: $0 target [target...]\n" unless (@ARGV);# At least one
30  
31  # Open pipe to read make (or gmake) output:
32  if ($have_gmake) {
33      open(MAKE, "gmake -n -W $ARGV[0] |");       # -W outdates target
34  } else {
35      # Rename target because if non-existent it's treated as out-of-date:
36      ($sample_target = $ARGV[0]) =~ s/$source_suffix$/$object_suffix/;
37      if (-e $sample_target) {    # If the sample target exists
38          $saved_target = "$sample_target"."~";   # Backup copy name
39          rename($sample_target, $saved_target);  # Squirrel away
40      }
41      open(MAKE, "make -n $sample_target |");     # Make treats as dated
42  }
43  
44  # Determine necessary include directives:
45  while (<MAKE>) {    # For each make-command output line
46      chop;           # Remove trailing newline
47      @cmd_line = split(/[ \t]+/, $_);            # Tokenize at whitespace
48  
49      while (@cmd_line) {
50          $make_token = shift (@cmd_line);        # For each token
51          if ($make_token =~ /^-I|^-D/) {         # Include/define?
52              $directive_token = $make_token;     # Yes, save it
53              if (! $is_directive{$directive_token}) {    # Not seen
54                  $is_directive{$directive_token} .= $directive_token;
55                  # Add to catenated string of include directories:
56                  $cpp_directives .= " ";         # (Catenation saves
57                  $cpp_directives .= $directive_token;# original order)
58              }
59          }
60      }   # End of while ($make_token = ...
61  }       # End of while (<MAKE>) {
62  
63  # Add any necessary include directories:
64  $cpp_directives .= " $add_include_dirs ";
65  
66  # For each source file named on command line
67  while (@ARGV) {                         # While there are arguments
68      undef %includes;                    # Reset array before next file
69      $source_file = shift;               # Save name for later use
70      if (! -r $source_file) {            # Can file be read?
71          print STDERR "Source file \"$source_file\" not readable.\n";
72          next;   # Try another source file, if available
73      }
74      # Preprocessor names all include directives:
75      open(CPP, "$cpp_cmd $cpp_directives $source_file |");
76  
77      # Create list of all included files:
78      while (<CPP>) {
79          s#//.*$##;                      # Delete C++ "//" comment
80          if (/^(#|#line)\s*\d+\s+["<](\S+)[">]\s+.*$/ &&
81            ! m.$ignore_include_dirs. ) { # Grab relevant includes
82                  $includes{$2} .= $2 unless $includes{$2};   # Save name
83          }   # End of if (/^ ...
84      }       # End of while (<CPP>) {
85  
86      # Report target name:
87      $_ = $source_file;
88      s/$source_suffix$/$object_suffix/;  # Create target name
89      print "$_ :";                       # Dependency or rules line
90  
91      # List the prerequisites for the target:
92      foreach $dependency (sort keys(%includes)) {
93          print " \\\n";  # continuation line
94          print "\t$includes{$dependency}";# Important: tab first
95      }
96      print "\n\n";                       # Empty lines between targets
97  }
98  rename($saved_target, $sample_target) if $saved_target;

B. Sample prototype Makefile:

# Make file to build program
#
CFLAGS = -g # for symbolic debugging
#
OBJS = module1.o module2.o
#
program: $(OBJS)
cc -o $@ $(OBJS)
#
# Object file dependencies:
#

C. Completed make file with object-file dependencies included:

# Make file to build program
#
CFLAGS = -g # for symbolic debugging
#
OBJS = module1.o module2.o
#
program: $(OBJS)
cc -o $@ $(OBJS)
#
# Object file dependencies:
#
module1.o : \
./module1.h \
module1.c

module2.o : \
module2.c

Listing 2: The zloop Bourne shell script lets you operate on selected compressed files.

A. Listing of the zloop program:

1  #! /bin/sh
2  # @(#) zloop  Loop through compressed files, running command on each
3  # Author: Jerry Peek, April 1990, updated July 1993
4  # Modified by Kees Hendrikse, February 1994
5  
6  Myname=`basename $0`    # Name of this program
7  Usage="Usage: $Myname 'command line to run' file.{Z|z|gz|zip}..."
8  
9  # Check command-line arguments:
10  case $# in
11      0|1) echo $Usage 1>&2 ; exit 1 ;;
12  esac
13  
14  # Save command quoting white space:
15  Cmd="$1"; shift         # shift away command argument
16  
17  for File                # For all remaining arguments (files)
18  do
19      case $File in
20          *.Z)    Zcat=zcat ;;
21          *.z)    Zcat=pcat ;;
22          *.gz)   Zcat=gzcat ;;
23          *.zip)  Zcat="unzip -c" ;;
24          *)      echo "File type of \"$File\" not recognized." >&2
25                  continue ;;
26      esac
27  
28      # Display a header, run the command, report any errors:
29      echo "
30  ==== $Myname: $Zcat $File | $Cmd ====" 1>&2
31      eval $Zcat $File \| $Cmd
32      Status=$?
33      case "$Status" in
34          0)  ;;
35          *)  echo "Note command that returned $Status exit status:
36              '$Zcat $File | $Cmd'" 1>&2 ;;
37      esac
38  done

B. Using zloop to print some compressed files:

$ ls ch*
ch01.Z   ch02.Z   ch03.Z   ch04.Z   ch05.Z
$ zloop 'pr | lp -d ast' ch0[1-3].Z

==== zloop: zcat ch01.Z | pr | lp -d ast ====
request id is ast-1904 (standard input)

==== zloop: zcat ch02.Z | pr | lp -d ast ====
request id is ast-1905 (standard input)

==== zloop: zcat ch03.Z | pr | lp -d ast ====
request id is ast-1906 (standard input)
$ []

C. Discarding the headers from the last example:

$ zloop 'pr | lp -d ast' ch0[1-3].Z 2>/dev/null
request id is ast-1907 (standard input)
request id is ast-1908 (standard input)
request id is ast-1909 (standard input)
$ []

D. Running grep to search for a text in compressed files:

$ zloop 'grep -i "System V"' ch0[12].Z

==== zloop: zcat ch01.Z | grep -i "System V" ====
Note command that returned 1 exit status:
		'/usr/bin/zcat ch01.Z | grep -i "System V"'

==== zloop: zcat ch02.Z | grep -i "System V" ====
1  #ifdef TERMIO                   /* System V or BSD4.3+ */
$ []