( arpi_esp | 2025. 05. 04., v – 19:39 )

ki kell probalni! kivancsi lennek az eredmenyre.

beadtam deepseek-nek egyik trukkos c iromanyom, siman megertette a kavarast, bar valamiert angolul valaszolt:

 

Mit csinal az alabbi fuggveny?

int func1(const char* path,const char* username){
int unlen=username ? strlen(username) : 0;
int n=0;
int fd=open(path,O_RDONLY);
if(fd<0) return 0;
off_t fsize=lseek(fd,0,SEEK_END);
char* raw=malloc(fsize+1);
lseek(fd,0,SEEK_SET);
fsize=read(fd,raw,fsize);
close(fd);
if(fsize<=0) return 0;
int i;
for(char* q=raw;q<raw+fsize;){
char* p=q; while(q<raw+fsize && *q!=10) q++; *q++=0;
if(!username || (!memcmp(p,username,unlen) && p[unlen]==':')){
for(i=0;i<n && strcmp(db[i],p);i++);
if(i>=n && n<DB_MAX) db[n++]=strdup(p);
} }
free(raw);
return n;
}

Analysis of the func1 Function

This function reads a file, processes its contents, and stores certain lines in a global database array. Here's what it does in detail:

Function Parameters

  • path: Path to a file to be read
  • username: Optional username string (can be NULL)

Key Operations

  1. File Handling:

    • Opens the file in read-only mode
    • Determines its size and reads the entire content into memory
    • Closes the file when done

  2. Line Processing:

    • Splits the file content into lines (by replacing newlines with null terminators)
    • For each line:
      • If no username was provided, processes all lines
      • If username was provided, only processes lines that start with that username followed by a colon
      • Checks if the line already exists in the global db array
      • If not, adds it to the array (up to DB_MAX entries)

  3. Return Value:

    • Returns the number of unique lines added to the database

Purpose

This appears to be a function that loads user-specific data (or all data if no user specified) from a configuration or database file into memory, while avoiding duplicates. The format suggests the file contains entries like "username:data".

The global db array stores these entries and grows as new ones are added (up to DB_MAX).

Speed: 1.2 t/s