# APUE-LinuxC

**Repository Path**: whc_softHardware/apue-linux-c

## Basic Information

- **Project Name**: APUE-LinuxC
- **Description**: APUE-LinuxC
- **Primary Language**: Unknown
- **License**: GPL-3.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2023-06-01
- **Last Updated**: 2023-09-12

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# codeRep

## 环境

## pmap - report memory map of a process

```c
#include <stdio.h>
#include <stdlib.h>

static int i=0;

int main()
{
    char* string ="helloworld\n";
    int j=0;

    printf("%d  %d  %s",i,j,string);

    getchar();
    exit(0);
}
```

使用pmap查看进程影像

```shell
whc@whc-virtual-machine:~/vsCodeProjects/APUE/file_system/fs$ pmap 67276727:   ./ccodeenv
000055d8df43a000      4K r-x-- ccodeenv
000055d8df63a000      4K r---- ccodeenv
000055d8df63b000      4K rw--- ccodeenv
000055d8e102c000    132K rw---   [ anon ]
00007f80baa62000   1948K r-x-- libc-2.27.so
00007f80bac49000   2048K ----- libc-2.27.so
00007f80bae49000     16K r---- libc-2.27.so
00007f80bae4d000      8K rw--- libc-2.27.so
00007f80bae4f000     16K rw---   [ anon ]
00007f80bae53000    164K r-x-- ld-2.27.so
00007f80bb061000      8K rw---   [ anon ]
00007f80bb07c000      4K r---- ld-2.27.so
00007f80bb07d000      4K rw--- ld-2.27.so
00007f80bb07e000      4K rw---   [ anon ]
00007ffdc0b48000    132K rw---   [ stack ]
00007ffdc0bd4000     12K r----   [ anon ]
00007ffdc0bd7000      8K r-x--   [ anon ]
ffffffffff600000      4K r-x--   [ anon ]
 total             4520K

```

## strace - trace system calls and signals

```c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main()
{
    putchar('a');
    write(1, "b", 1);

    putchar('a');
    write(1, "b", 1);

    putchar('a');
    write(1, "b", 1);

    exit(0);
}

```

```shell
whc@whc-virtual-machine:~/vsCodeProjects/APUE/io/sysio$ strace ./ab 
execve("./ab", ["./ab"], 0x7ffd59001ae0 /* 36 vars */) = 0
brk(NULL)                               = 0x562f69eba000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=100054, ...}) = 0
mmap(NULL, 100054, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7ff7799f3000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240\35\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=2030928, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7ff7799f1000
mmap(NULL, 4131552, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ff7793f2000
mprotect(0x7ff7795d9000, 2097152, PROT_NONE) = 0
mmap(0x7ff7797d9000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7ff7797d9000
mmap(0x7ff7797df000, 15072, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ff7797df000
close(3)                                = 0
arch_prctl(ARCH_SET_FS, 0x7ff7799f24c0) = 0
mprotect(0x7ff7797d9000, 16384, PROT_READ) = 0
mprotect(0x562f69c58000, 4096, PROT_READ) = 0
mprotect(0x7ff779a0c000, 4096, PROT_READ) = 0
munmap(0x7ff7799f3000, 100054)          = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 4), ...}) = 0
brk(NULL)                               = 0x562f69eba000
brk(0x562f69edb000)                     = 0x562f69edb000
write(1, "b", 1b)                        = 1
write(1, "b", 1b)                        = 1
write(1, "b", 1b)                        = 1
write(1, "aaa", 3aaa)                      = 3
exit_group(0)                           = ?
+++ exited with 0 +++
```