libdi(3) Library Functions Manual libdi(3)
Name
libdi - disk information library
Synopsis
Initialization
#include <di.h>
void * di_initialize (void);
int di_process_options (void *di_data, int targc, const char *targv [],
int offset);
void di_cleanup (void *di_data);
const char *di_version (void);
Options
int di_check_option (void *di_data, int option);
void di_format_iter_init (void *di_data);
int di_format_iterate (void *di_data);
Getting data
int di_get_all_disk_info (void *di_data);
int di_iterate_init (void *di_data, int iteroption);
typedef struct {
const char *strdata [DI_DISP_MAX]; /* string data */
int index; /* internal index value */
int doPrint; /* printable flag based on options */
int printFlag; /* print result flag */
int isLocal; /* filesystem is local */
int isReadOnly; /* filesystem is read-only */
int isLoopback; /* filesystem is a loopback filesystem */
} di_pub_disk_info_t;
const di_pub_disk_info_t * di_iterate (void *di_data);
int di_get_scale_max (void *di_data, int index,
int valueidxA, int valueidxB, int valueidxC);
double di_get_scaled (void *di_data, int index,
int scaleidx, int valueidxA, int valueidxB, int valueidxC);
void di_disp_scaled (void *di_data, char *buff, long buffsz,
int index, int scaleidx,
int valueidxA, int valueidxB, int valueidxC);
double di_get_perc (void *di_data, int index,
int valueidxA, int valueidxB,
int valueidxC, int valueidxB, int valueidxE);
void di_disp_perc (void *di_data, char *buff, long buffsz,
int index,
int valueidxA, int valueidxB,
int valueidxC, int valueidxB, int valueidxE);
Overview
Initialization
di_initialize returns a pointer to a di_data structure, used in all of
the other library calls. The returned pointer must be freed with
di_cleanup.
di_process_options processes the arguments to di. These are passed as
strings via an argv structure as if on the command line. If no call to
di_process_options is made, di will use the defaults and the DI_ARGS
environment variable will not be processed.
If the return value from di_process_options is not DI_EXIT_NORM,
di_cleanup should be called and processing stopped.
di_cleanup frees all allocated data.
Options
di_check_option returns the value of the specified option. All options
will return a boolean value, excepting: DI_OPT_DEBUG,
DI_OPT_FMT_STR_LEN, DI_OPT_SCALE and DI_OPT_BLOCK_SZ.
option may be one of:
DI_OPT_POSIX_COMPAT
DI_OPT_QUOTA_CHECK
DI_OPT_DISP_CSV
DI_OPT_DISP_CSV_TAB
DI_OPT_EXCL_LOOPBACK
DI_OPT_DISP_JSON
DI_OPT_DISP_TOTALS
DI_OPT_DISP_HEADER
DI_OPT_DISP_ALL
DI_OPT_LOCAL_ONLY
DI_OPT_NO_SYMLINK
DI_OPT_DEBUG
DI_OPT_FMT_STR_LEN
DI_OPT_SCALE
DI_OPT_BLOCK_SZ
di_format_iter_init initializes the format string iterator.
di_format_iterate iterates through each format character in the format
string. Note that di allows unrecognized format characters. In the
main di program, these are printed as-is.
Getting Data
di_get_all_disk_info retrieves and processes all of the disk
information from the operating system.
If the return value from di_get_all_disk_info is not DI_EXIT_NORM,
di_cleanup should be called and processing stopped.
di_iterate_init initializes the disk information iterator. iteroption
is one of DI_ITER_PRINTABLE or DI_ITER_ALL. If DI_ITER_PRINTABLE is
specified, only the partitions with the doPrint flag set will be
returned by the iterator.
di_iterate iterates through the filesystems, returning a
di_pub_disk_info_t structure for each filesystem. If the --totals flag
was specified as an option, the totals will be the last item returned
by the iterator.
di_get_scale_max gets the maximum scaling unit for the space value.
index is the index from the di_pub_disk_info_t structure.
The valueidx arguments indicate which disk space values to use to
calculate the the space value. The formula is: A - (B - C). Valid
combinations are:
DI_SPACE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE // total
DI_SPACE_TOTAL, DI_SPACE_FREE, DI_SPACE_AVAIL // used
DI_SPACE_TOTAL, DI_SPACE_FREE, DI_VALUE_NONE // used
DI_SPACE_TOTAL, DI_SPACE_AVAIL, DI_VALUE_NONE // used
DI_SPACE_FREE, DI_VALUE_NONE, DI_VALUE_NONE // free
DI_SPACE_AVAIL, DI_VALUE_NONE, DI_VALUE_NONE // free
DI_INODE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE // inode total
DI_INODE_TOTAL, DI_INODE_FREE, DI_VALUE_NONE // inodes used
DI_INODE_FREE, DI_VALUE_NONE, DI_VALUE_NONE // inodes free
di_get_scaled gets a space value scaled according to the scaling unit.
index is the index from the di_pub_disk_info_t structure.
scaleidx is the scaling index to use. Use a scaling index returned
from di_get_scale_max or use one of the following values:
DI_SCALE_BYTE
DI_SCALE_KILO
DI_SCALE_MEGA
DI_SCALE_GIGA
DI_SCALE_TERA
DI_SCALE_PETA
DI_SCALE_EXA
DI_SCALE_ZETTA
DI_SCALE_YOTTA
DI_SCALE_RONNA
DI_SCALE_QUETTA
The valueidx arguments indicate which disk space values to use to
calculate the the space value. The formula is: A - (B - C). See
di_get_scale_max for a list of valid combinations.
di_disp_scaled gets a space value scaled according to the scaling unit,
and creates a string that can be printed.
buff is the character string where the string will be stored.
buffsz is the size of the character string.
index is the index from the di_pub_disk_info_t structure.
scaleidx is the scaling index to use. Use a scaling index returned
from di_get_scale_max or one of the values as listed in di_get_scaled.
The valueidx arguments indicate which disk space values to use to
calculate the the space value. The formula is: A - (B - C). See
di_get_scale_max for a list of valid combinations.
di_get_perc retrieves the disk space value as a percentage.
index is the index from the di_pub_disk_info_t structure.
The valueidx arguments indicate which disk space values to use to
calculate the percentage. The formula is: (A - B) / (C - (D - E)).
Valid combinations are:
/* percent used */
DI_SPACE_TOTAL, DI_SPACE_AVAIL,
DI_SPACE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE
/* percent used */
DI_SPACE_TOTAL, DI_SPACE_FREE,
DI_SPACE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE
/* percent used, BSD style */
DI_SPACE_TOTAL, DI_SPACE_FREE,
DI_SPACE_TOTAL, DI_VALUE_FREE, DI_VALUE_AVAIL
/* percent free */
DI_SPACE_AVAIL, DI_VALUE_NONE,
DI_SPACE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE,
/* percent free */
DI_SPACE_FREE, DI_VALUE_NONE,
DI_SPACE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE,
/* inodes used */
DI_INODE_TOTAL, DI_INODE_AVAIL,
DI_INODE_TOTAL, DI_VALUE_NONE, DI_VALUE_NONE
di_disp_perc retrieves the disk space value as a percentage and creates
a string that can be printed.
buff is the character string where the string will be stored.
buffsz is the size of the character string.
index is the index from the di_pub_disk_info_t structure.
The valueidx arguments indicate which disk space values to use to
calculate the percentage. The formula is: (A - B) / (C - (D - E)).
See di_get_perc for valid combinations.
Example
/* this code is in the public domain */
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>
#include <di.h>
enum {
HAVE_SPACE = 0,
NO_SPACE = 1,
};
int
check_space (const char *fn, double space_wanted) {
void *di_data;
int targc;
const char *targv [10];
int exitflag;
const di_pub_disk_info_t *pub;
int rval = NO_SPACE;
int count;
targc = 1;
targv [0] = fn;
targv [1] = NULL;
di_data = di_initialize ();
exitflag = di_process_options (di_data, targc, targv, 0);
if (exitflag != DI_EXIT_NORM) {
di_cleanup (di_data);
exit (exitflag);
}
exitflag = di_get_all_disk_info (di_data);
if (exitflag != DI_EXIT_NORM) {
di_cleanup (di_data);
exit (exitflag);
}
count = di_iterate_init (di_data, DI_ITER_PRINTABLE);
while ((pub = di_iterate (di_data)) != NULL) {
double dval;
/* compare terabytes available */
dval = di_get_scaled (di_data, pub->index, DI_SCALE_TERA,
DI_SPACE_AVAIL, DI_VALUE_NONE, DI_VALUE_NONE);
if (dval >= space_wanted) {
rval = HAVE_SPACE;
}
}
di_cleanup (di_data);
return rval;
}
int
main (int argc, char *argv []) {
const char *fn = "/home/bll/s/di";
double spwant = 0.2; /* terabytes */
bool rval;
if (argc > 1) {
fn = argv [1];
}
if (argc > 2) {
spwant = atof (argv [2]);
}
rval = check_space (fn, spwant);
if (rval == NO_SPACE) {
fprintf (stdout, "Not enough disk space\n");
}
if (rval == HAVE_SPACE) {
fprintf (stdout, "Enough disk space\n");
}
return rval;
}
Compile and Link
dilibd=$HOME/local/lib
diinc=$(pkg-config --with-path ${dilibd}/pkgconfig --cflags di)
dilibs=$(pkg-config --with-path ${dilibd}/pkgconfig --libs di)
cc -o tt ${diinc} tt.c -Wl,-R${dilibd} ${dilibs})
Example Run
bll-g7:bll$ ./tt /home/bll 0.5
Not enough disk space
bll-g7:bll$ ./tt /home/bll 0.1
Enough disk space
See Also
df(1), di(1)
Bugs
Open a ticket at https://sourceforge.net/p/diskinfo-di/tickets/
Send bug reports to: brad.lanam.di @ gmail.com
Links
Home Page: https://diskinfo-di.sourceforge.io/
Wiki: https://sourceforge.net/p/diskinfo-di/wiki/Home/
Change Log: https://sourceforge.net/p/diskinfo-di/wiki/ChangeLog/
Author
Copyright 1994-2025 by Brad Lanam Pleasant Hill, CA
28 Jan 2025 libdi(3)
di 6.1.0 - Generated Mon Nov 3 18:20:29 CST 2025