Obtain the file system information (Disk information) in linux)

Obtain the file system information (Disk information) in linux)

The source code is as follows:

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// File system information structure struct fileSystem_info {char fileSystem_format [8]; char fileSystem_total_capacity [11]; char fileSystem_free_capacity [11]; char fileSystem_permissions [3];}; /* Get File System information */int get_fileSystem_info (const char * fileSystem_name, struct fileSystem_info * fi);/* block to kbyte */static unsigned long kscale (unsigned long m_block, unsigned long m_kbyte);/* convert size to gb mb kb */static char * convert_size (float m_size, char * dest); int main () {char buf [1024]; struct fileSystem_info fileSysInfo; get_fileSystem_info ("/", & fileSysInfo); printf ("% s \ n", fileSysInfo. fileSystem_format); printf ("% s \ n", fileSysInfo. fileSystem_free_capacity); printf ("% s \ n", fileSysInfo. fileSystem_total_capacity); printf ("% s \ n", fileSysInfo. fileSystem_permissions); return 0;}/* Get File System information */int get_fileSystem_info (const char * fileSystem_name, struct fileSystem_info * fi) {struct statfs buf; float fileSystem_total_size = 0; float fileSystem_free_size = 0; if (statfs (fileSystem_name, & buf) {fprintf (stderr, "statfs % s \ n", strerror (errno); return-1 ;} switch (buf. f_type) {case 0xEF51: case 0xEF53: sprintf (fi-> fileSystem_format, "EXT"); break; case 0x4d44: sprintf (fi-> fileSystem_format, "FAT"); break; case 0x5425544e: sprintf (fi-> fileSystem_format, "NIFS"); break; default: sprintf (fi-> fileSystem_format, "unknown"); break ;} bzero (& fi-> fileSystem_total_capacity, sizeof (fi-> fileSystem_total_capacity); bzero (& fi-> fileSystem_free_capacity, sizeof (fi-> fileSystem_free_capacity )); printf ("blocks % ld \ n", buf. f_blocks); printf ("bfree % ld \ n", buf. f_bfree); printf ("bsize % ld \ n", buf. f_bsize); fileSystem_total_size = (float) (kscale (buf. f_blocks, buf. f_bsize); fileSystem_free_size = (float) (kscale (buf. f_bfree, buf. f_bsize); printf ("total % f \ n", fileSystem_total_size); printf ("free % f \ n", fileSystem_free_size); convert_size (fileSystem_total_size, fi-> bytes ); convert_size (fileSystem_free_size, fi-> packages); bzero (fi-> fileSystem_permissions, sizeof (fi-> fileSystem_permissions); sprintf (fi-> fileSystem_permissions, "rw "); return 0;}/* block to kbyte */static unsigned long kscale (unsigned long m_block, unsigned long m_kbyte) {return (unsigned long) m_block * m_kbyte + 1024/2) /1024;}/* convert size to gb mb kb */static char * convert_size (float m_size, char * dest) {if (m_size/1024.0) /1024.0)> = 1.0) {sprintf (dest, "% 0.2fGB", (m_size/1024.0)/1024.0);} else if (m_size/1024.0)> = 1.0) {sprintf (dest, "% 0.2fMB", (m_size/1024);} else {sprintf (dest, "% 0.2fKB", m_size);} return dest ;}
     
    
   
  

Summary:
1. struct statfs struct information reference: http://blog.csdn.net/u011641885/article/details/46919027
2. Use the float type for fileSystem_total_size to ensure higher accuracy. The fdisk source code in buysbox uses integer division, which is about 4 homes and 5 inputs.
3. the unsigned long type is used in the kscale function because m_block and m_byte are originally in the long type. The result of multiplication exceeds the long type and can represent the data bit.