আমি মনে করি যে পাইপ ব্যবহার করা (traditionalতিহ্যবাহী উপায়) কিছুটা বেশি দ্রুত; আমার বাক্সে আমি straceকমান্ড ব্যবহার করে যা চলছে তা দেখতে:
পাইপ ছাড়াই:
toc@UnixServer:~$ strace wc -l < wrong_output.c
execve("/usr/bin/wc", ["wc", "-l"], [/* 18 vars */]) = 0
brk(0) = 0x8b50000
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap2(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb77ad000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=29107, ...}) = 0
mmap2(NULL, 29107, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb77a5000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/i386-linux-gnu/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0p\222\1\0004\0\0\0"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1552584, ...}) = 0
mmap2(NULL, 1563160, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb7627000
mmap2(0xb779f000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x178) = 0xb779f000
mmap2(0xb77a2000, 10776, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb77a2000
close(3) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7626000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb76268d0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xb779f000, 8192, PROT_READ) = 0
mprotect(0x804f000, 4096, PROT_READ) = 0
mprotect(0xb77ce000, 4096, PROT_READ) = 0
munmap(0xb77a5000, 29107) = 0
brk(0) = 0x8b50000
brk(0x8b71000) = 0x8b71000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=5540198, ...}) = 0
mmap2(NULL, 2097152, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7426000
mmap2(NULL, 1507328, PROT_READ, MAP_PRIVATE, 3, 0x2a8) = 0xb72b6000
close(3) = 0
open("/usr/share/locale/locale.alias", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=2570, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb77ac000
read(3, "# Locale name alias data base.\n#"..., 4096) = 2570
read(3, "", 4096) = 0
close(3) = 0
munmap(0xb77ac000, 4096) = 0
open("/usr/share/locale/fr_FR.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/fr_FR.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/fr_FR/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/fr.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/fr.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/fr/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale-langpack/fr_FR.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale-langpack/fr_FR.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale-langpack/fr_FR/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale-langpack/fr.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale-langpack/fr.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale-langpack/fr/LC_MESSAGES/coreutils.mo", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=316721, ...}) = 0
mmap2(NULL, 316721, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7268000
close(3) = 0
open("/usr/lib/i386-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=26064, ...}) = 0
mmap2(NULL, 26064, PROT_READ, MAP_SHARED, 3, 0) = 0xb7261000
close(3) = 0
read(0, "#include<stdio.h>\n\nint main(int "..., 16384) = 180
read(0, "", 16384) = 0
fstat64(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7260000
write(1, "13\n", 313
) = 3
close(0) = 0
close(1) = 0
munmap(0xb7260000, 4096) = 0
close(2) = 0
exit_group(0) = ?
এবং পাইপ সহ:
toc@UnixServer:~$ strace cat wrong_output.c | wc -l
execve("/bin/cat", ["cat", "wrong_output.c"], [/* 18 vars */]) = 0
brk(0) = 0xa017000
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap2(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb774b000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=29107, ...}) = 0
mmap2(NULL, 29107, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7743000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/i386-linux-gnu/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0p\222\1\0004\0\0\0"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1552584, ...}) = 0
mmap2(NULL, 1563160, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb75c5000
mmap2(0xb773d000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x178) = 0xb773d000
mmap2(0xb7740000, 10776, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb7740000
close(3) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb75c4000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb75c48d0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xb773d000, 8192, PROT_READ) = 0
mprotect(0x8051000, 4096, PROT_READ) = 0
mprotect(0xb776c000, 4096, PROT_READ) = 0
munmap(0xb7743000, 29107) = 0
brk(0) = 0xa017000
brk(0xa038000) = 0xa038000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=5540198, ...}) = 0
mmap2(NULL, 2097152, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb73c4000
mmap2(NULL, 1507328, PROT_READ, MAP_PRIVATE, 3, 0x2a8) = 0xb7254000
close(3) = 0
fstat64(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
open("wrong_output.c", O_RDONLY|O_LARGEFILE) = 3
fstat64(3, {st_mode=S_IFREG|0664, st_size=180, ...}) = 0
read(3, "#include<stdio.h>\n\nint main(int "..., 32768) = 180
write(1, "#include<stdio.h>\n\nint main(int "..., 180) = 180
read(3, "", 32768) = 0
close(3) = 0
close(1) = 0
close(2) = 0
exit_group(0) = ?
13
আপনি ভাল বেঞ্চমার্কিংয়ের জন্য আরও দীর্ঘতর কমান্ডের সাহায্যে কিছু পরীক্ষা করতে পারেন straceএবং timeকমান্ড করতে পারেন ।
catএকটি পরিচয় পাইপ । এটি কেবলমাত্র তার ইনপুটটিকে তার আউটপুটে প্রবাহিত করে। শৃঙ্খলে থাকা দ্বিতীয় প্রোগ্রামটি যদি আপনার একই আর্গুমেন্টে পাস করেcat(বা স্ট্যান্ডার্ড ইনপুট থেকে, যদি আপনি কোনও যুক্তি পাস করেন না) থেকে নিতে পারেন, তবেcatএটি একেবারেই অকেজো এবং কেবলমাত্র একটি অতিরিক্ত প্রক্রিয়া কাঁটাযুক্ত হওয়ার ফলে এবং একটি অতিরিক্ত পাইপ হওয়ার ফলস্বরূপ তৈরি