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first-free-port : meilleure gestion des erreurs

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This commit is contained in:
Hippolyte Chauvin 2023-12-04 23:07:42 +01:00
parent c16666a3f9
commit 519f9d415f
1 changed files with 17 additions and 4 deletions
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21
src/first-free-port.c
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@ -3,6 +3,7 @@
#include <fcntl.h> #include <fcntl.h>
#include <sysexits.h> #include <sysexits.h>
#include <string.h> #include <string.h>
#include <errno.h>
#define MIN_TCP_PORT 1 #define MIN_TCP_PORT 1
#define TCP_TABLE "/proc/net/tcp" #define TCP_TABLE "/proc/net/tcp"
@ -12,6 +13,13 @@
#define LISTENING_HEX "0A" #define LISTENING_HEX "0A"
#define PORTS_BLOCKS_TO_ALLOW 4 #define PORTS_BLOCKS_TO_ALLOW 4
/**
* Print a nice error message
*/
static void print_error(char *name, const char *message) {
fprintf(stderr, "%s: %s\n", name, message);
}
/** /**
* Get all the listening TCP ports * Get all the listening TCP ports
*/ */
@ -81,20 +89,25 @@ int main(int argc, char *argv[]) {
} }
if (!is_valid_tcp_port(current_port)) { if (!is_valid_tcp_port(current_port)) {
fprintf(stderr, "%s: provide a valid TCP port number as first argument.\n", argv[0]); print_error(argv[0], "provide a valid TCP port number as first argument.");
return EX_USAGE; return EX_USAGE;
} }
// Open TCP table // Open TCP table
FILE *tcp_table_fptr = fopen(TCP_TABLE, "r"); FILE *tcp_table_fptr = fopen(TCP_TABLE, "r");
if (tcp_table_fptr == NULL) { if (tcp_table_fptr == NULL) {
fprintf(stderr, "%s: error opening the TCP table.\n", argv[0]); print_error(argv[0], "error opening the TCP table.");
return EX_OSFILE; return errno;
} }
unsigned short *listening_ports = malloc(PORTS_BLOCKS_TO_ALLOW * sizeof(unsigned short)); unsigned short *listening_ports = malloc(PORTS_BLOCKS_TO_ALLOW * sizeof(unsigned short));
listening_ports = get_listening_ports(listening_ports, tcp_table_fptr); listening_ports = get_listening_ports(listening_ports, tcp_table_fptr);
if (fclose(tcp_table_fptr) != 0) {
print_error(argv[0], "can't close the TCP table.");
return errno;
}
// Check if the current port is available, add // Check if the current port is available, add
while (!is_port_available(current_port, listening_ports)) { while (!is_port_available(current_port, listening_ports)) {
current_port++; current_port++;
@ -106,7 +119,7 @@ int main(int argc, char *argv[]) {
printf("%d\n", current_port); printf("%d\n", current_port);
return EXIT_SUCCESS; return EXIT_SUCCESS;
} else { } else {
fprintf(stderr, "%s: no more ports available; how did you fuck up that bad ???\n", argv[0]); print_error(argv[0], "no more ports available; how did you fuck up that bad ???");
return EX_TEMPFAIL; return EX_TEMPFAIL;
} }
} }