calc.c

   1 /* depend: */
   2 /* cflags: */
   3 /* linker: atoi.o fdprintf.o */
   4
   5 //#include <malloc.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <unistd.h>
   9
  10 #include "atoi.h"
  11 #include "fdprintf.h"
  12
  13 /* constants */
  14
  15 //#define BUFFER_SIZE 4096
  16 #define BUFFER_SIZE 256
  17
  18 /* macros */
  19
  20 #define CEIL(x, y) (((x) + (y) - 1) / (y))
  21 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
  22 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
  23
  24 /* verbose */
  25
  26 #define ERROR 0
  27 #define WARNING 1
  28 #define INFO 2
  29 #define DEBUG 3
  30
  31 #define VERBOSE(level, statement...) do { if (level <= verbose) { statement; } } while(0)
  32
  33 /* gobal variables */
  34
  35 char *progname = NULL;
  36 int verbose = 2;
  37
  38 /* help function */
  39
  40 int usage (int ret)
  41 {
  42     int fd = ret ? stdfderr : stdfdout;
  43     fdprintf (fd, "usage: %s\n", progname);
  44     fdprintf (fd, " -h : help message\n");
  45     fdprintf (fd, " -v : verbose level (%d)\n", verbose);
  46
  47     return ret;
  48 }
  49
  50 /* main function */
  51
  52 int main (int argc, char *argv[])
  53 {
  54     char buffer[BUFFER_SIZE + 1] = {0};
  55     char *pt = buffer;
  56     int i = 0, j = 0, n;
  57
  58     /* program name */
  59
  60     progname = argv[0];
  61     while (progname[i] != '\0') {
  62         if ((progname[i] == '/') || (progname[i] == '\\')) {
  63             progname += i + 1;
  64             i = 0;
  65         } else {
  66             i++;
  67         }
  68     }
  69
  70     /* argument processing */
  71
  72      while (argc-- > 1) {
  73         char *arg = *(++argv);
  74         if (arg[0] != '-') {
  75             PRINTERR ("%s: invalid option -- %s\n", progname, arg);
  76             return usage (1);
  77         }
  78         char c = arg[1];
  79         switch (c) {
  80         case 'v':
  81             arg = (arg[2]) ? arg + 2 : (--argc > 0) ? *(++argv) : NULL;
  82             if (arg == NULL) {
  83                 PRINTERR ("%s: missing verbose level\n", progname);
  84                 return usage (1);
  85             }
  86             verbose = atoi (arg);
  87             break;
  88         case 'h':
  89         default:
  90             return usage (c != 'h');
  91         }
  92     }
  93
  94     /* read from input stream */
  95
  96     while ((n = read (stdfdin, pt, BUFFER_SIZE - (pt - buffer))) != 0) {
  97         VERBOSE (DEBUG, PRINTOUT ("read %d bytes\n", n));
  98         n += (pt - buffer);
  99
 100         /* look for end of line */
 101         for (i = 0, j = 0; i < n; i++) {
 102             if (buffer[i] == '\n') {
 103                 buffer[i] = 0;
 104                 VERBOSE (DEBUG, PRINTOUT ("line(%d): %s\n", j, buffer + j));
 105                 //fsync (stdfdout);
 106                 fflush (stdout);
 107                 j = i + 1;
 108             }
 109         }
 110
 111         /* keep remainding */
 112         if (j < n) {
 113             for (i = 0; i < n - j; i++) {
 114                 buffer[i] = buffer[i + j];
 115             }
 116             pt = buffer + n - j;
 117             for (i = n - j; i < BUFFER_SIZE; i++) {
 118                 buffer[i] = 0;
 119             }
 120         }
 121     }
 122
 123     return 0;
 124 }
 125
 126 // test: calc.exe -h
 127 // test: calc.exe -h | awk '/usage:/ { rc=1 } END { exit (1-rc) }'
 128 // test: calc.exe -_ 2> /dev/null | awk 'END { if (NR == 0) { exit(0) } else exit (1) }'
 129 // test: calc.exe -_ 2>&1 | awk '/usage:/ { rc=1 } END { exit (1-rc) }'
 130 // test: echo "foo\nbar\nfoobar" | calc.exe -v3
 131
 132 /* vim: set ts=4 sw=4 et: */