Red Hat ENTERPRISE LINUX 3 - DEBUGGING WITH GDB Manual page 349

Appendix D. gdb Remote Serial Protocol
D.7.10.1. open
Synopsis: int open(const char *pathname, int flags);
int open(const char *pathname, int flags, mode_t mode);
Request:
Fopen,pathptr/len,flags,mode
is the bitwise or of the following values:
flags
O_CREAT
If the file does not exist it will be created. The host rules apply as far as file ownership and time
stamps are concerned.
O_EXCL
When used with O_CREAT, if the file already exists it is an error and open() fails.
O_TRUNC
If the file already exists and the open mode allows writing (O_RDWR or O_WRONLY is given)
it will be truncated to length 0.
O_APPEND
The file is opened in append mode.
O_RDONLY
The file is opened for reading only.
O_WRONLY
The file is opened for writing only.
O_RDWR
The file is opened for reading and writing.
Each other bit is silently ignored.
is the bitwise or of the following values:
mode
S_IRUSR
User has read permission.
S_IWUSR
User has write permission.
S_IRGRP
Group has read permission.
S_IWGRP
Group has write permission.
S_IROTH
Others have read permission.
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