free.c

Linux下进程监控相关源代码

/* free.c - a /proc implementation of free */
/* Dec14/92 by Brian Edmonds */
/* Thanks to Rafal Maszkowski for the Total line */

#include "proc/sysinfo.h"
#include "proc/version.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <getopt.h>

/* set this to whatever you want by default */
int byteshift = 10  ;
int total = 0;

int main( int argc, char **argv ) {
    char buf1[80], buf2[80];
    char *titles[6], name[32];
    int i, n = 0, col[6] = {0}, rtime = 0, old_fmt = 0, first_line;
    int old_meminfo = 0;
    long long **mem;

    static int sum[6]; /* statics get initialized to zero */

    /* check startup flags */
    while( (i = getopt( argc, argv, "bkmos:tV") ) != -1 )
        switch (i) {
        case 'b': byteshift = 0; break;
        case 'k': byteshift = 10; break;
        case 'm': byteshift = 20; break;
        case 'o': old_fmt = 1; break;
        case 's': rtime = 1000000 * atof(optarg); break;
        case 't': total = 1; break;
	case 'V': display_version(); exit(0);
        default:
	  fprintf(stderr, "usage: %s [-b|-k|-m] [-o] [-s delay] [-t] [-V]\n", argv[0]);
	  return 1;
    }

    /* redirect stdin to /proc/meminfo */
    if (linux_version_code < LINUX_VERSION(2,0,0)) {
        close(0);
        if (open( "/proc/meminfo", O_RDONLY ) < 0) {
            perror("open");
            return 2;
        }
    }
    do {
        if (linux_version_code < LINUX_VERSION(2,0,0)) {
            for(i=0; i<6; i++)
                sum[i]=0;
            first_line = 1;
            /* get the column titles */
            fseek(stdin, 0L, SEEK_SET);
            fgets( buf1, 80, stdin );
            for (i=0; i<6; i++) {
                titles[i] = strtok( ( i ? NULL : buf1 ), " \t:\n" );
                if (!titles[i]) {
                    if (i != 5) {
                        fprintf( stderr, "free: error reading /proc/meminfo\n" );
                        return 3;
                    } else
                        ++old_meminfo;
                }
            }
            
            if (old_meminfo) {
                fprintf(stdout, "%-7s %10s %10s %10s %10s %10s\n",
                        "", titles[0], titles[1], titles[2], titles[3],
                        titles[4]);
            } else {
                fprintf(stdout, "%-7s %10s %10s %10s %10s %10s %10s\n",
                        "", titles[0], titles[1], titles[2], titles[3],
                        titles[4], titles[5]);
            }
            
            /* read and translate data lines */
            while (fgets(buf2, 80, stdin)) {
                if (old_meminfo) {
                    n = sscanf(buf2, "%s %d %d %d %d %d", name,
                               &col[0], &col[1], &col[2], &col[3], &col[4]);
                } else {
                    n = sscanf(buf2, "%s %d %d %d %d %d %d", name,
                               &col[0], &col[1], &col[2], &col[3], &col[4],
                               &col[5]);
                }
                if (n < 4)
                    continue;
                fprintf( stdout, "%-7s", name );
                for (i=1 ; i<n ; i++) {
                    fprintf(stdout, " %10d", col[i-1]>>byteshift);
                    sum[i-1] += col[i-1];
                }
                fputc('\n', stdout);
                if (first_line && !old_fmt) {
                    first_line = 0;
                    fprintf( stdout, "-/+ buffers: %16d %10d\n",
                             (col[1] - col[4] - col[5])>>byteshift,
                             (col[2] + col[4] + col[5])>>byteshift);
                }
            }
            if (total == 1) {
                fprintf( stdout, "Total: ");
                for( i=1 ; i<n ; i++ )
                    fprintf(stdout, " %10d", sum[i-1]>>byteshift);
                fputc('\n', stdout);
            }
        } else {
            /* memory printing from top.c using meminfo() */
            if (!(mem = meminfo ()) || mem[meminfo_main][meminfo_total] == 0) {
                fprintf (stderr, "Cannot get size of memory from /proc/meminfo\n");
                exit (1);
            }
            printf("             total       used       free     shared    buffers     cached\n");
            printf ("%-7s %10Ld %10Ld %10Ld %10Ld %10Ld %10Ld\n", "Mem:",
                    mem[meminfo_main][meminfo_total] >> byteshift,
                    mem[meminfo_main][meminfo_used] >> byteshift,
                    mem[meminfo_main][meminfo_free] >> byteshift,
                    mem[meminfo_main][meminfo_shared] >> byteshift,
                    mem[meminfo_main][meminfo_buffers] >> byteshift,
                    mem[meminfo_main][meminfo_cached] >> byteshift);
            if (!old_fmt) printf("-/+ buffers/cache: %10Ld %10Ld\n", 
                   (mem[meminfo_main][meminfo_used]
                    -mem[meminfo_main][meminfo_buffers]
		    -mem[meminfo_main][meminfo_cached])>> byteshift,
                   (mem[meminfo_main][meminfo_free]
                    +mem[meminfo_main][meminfo_buffers]
		    +mem[meminfo_main][meminfo_cached])>> byteshift);
            printf ("%-7s %10Ld %10Ld %10Ld\n", "Swap:",
                    mem[meminfo_swap][meminfo_total] >> byteshift,
                    mem[meminfo_swap][meminfo_used] >> byteshift,
                    mem[meminfo_swap][meminfo_free] >> byteshift);
            if (total == 1) printf("%-7s %10Ld %10Ld %10Ld\n", "Total:",
                       (mem[meminfo_main][meminfo_total] +
                        mem[meminfo_swap][meminfo_total]) >> byteshift,
                       (mem[meminfo_main][meminfo_used] +
                        mem[meminfo_swap][meminfo_used]) >> byteshift,
                       (mem[meminfo_main][meminfo_free] +
                        mem[meminfo_swap][meminfo_free]) >> byteshift);
        }
        
        if (rtime) {
	    fputc('\n', stdout);
	    fflush(stdout);
	    usleep(rtime);
	}
    } while (rtime);

    return 0;
}