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mark's questions

Martin Hope
mark
Asked: 2023-07-29 01:38:31 +0800 CST
  • 6

Considere a seguinte transcrição bash:

~$ x="echo -n abc "

~$ $x && echo xyz
abcxyz

~$

Por curiosidade (por favor, me permita), eu quero ter uma variável bash contendo o echo -ncomando gerando algo. Eu quero saber se é possível defini-lo de forma a preservar o espaço à direita.

Uma opção óbvia é usar as aspas:

~$ x="echo -n \"abc \""

~$ $x && echo xyz
"abc "xyz

~$

Mas essas citações poluem a produção.

Claro, posso acrescentar o espaço ao segundo comando echo:

~$ x="echo -n abc "

~$ $x && echo " xyz"
abc xyz

~$

Mas o objetivo da pergunta é entender se xpode ser alterado de forma que $xrepresente echo -no espaço à direita sem aspas redundantes na saída.

Muito obrigado.

bash
Martin Hope
mark
Asked: 2023-05-10 00:08:36 +0800 CST
  • 5

No momento, o uso localno shell de nível superior falha:

/tmp/tmp.TvdqDYLG9T$ local x=1
bash: local: can only be used in a function

/tmp/tmp.TvdqDYLG9T$ echo $x


/tmp/tmp.TvdqDYLG9T$

Minha justificativa para querer que funcione é que quero testar minha função bash copiando/colando fragmentos do código no console do shell e testando-o lá. Mas eu não posso, por causa do local. Tenho que colar primeiro em um bloco de notas, remover locale depois colar no console.

Existe uma maneira melhor?

bash
Martin Hope
mark
Asked: 2023-05-05 21:37:47 +0800 CST
  • 7

Aqui está minha linha de comando docker:

mark@L-R910LPKW:~$ docker run -v /etc/ssl:/etc/ssl -v /usr/local/share/ca-certificates:/usr/local/share/ca-certificates -v /usr/share/ca-certificates:/usr/share/ca-certificates curlimages/curl -ksvo /dev/null https://registry.yarnpkg.com/csstype/-/csstype-3.0.8.tgz
*   Trying 104.16.19.35:443...
* Connected to registry.yarnpkg.com (104.16.19.35) port 443 (#0)
* ALPN: offers h2,http/1.1
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [88 bytes data]
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
} [1 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [155 bytes data]
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
{ [6 bytes data]
* TLSv1.3 (IN), TLS handshake, Certificate (11):
{ [3297 bytes data]
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
{ [264 bytes data]
* TLSv1.3 (IN), TLS handshake, Finished (20):
{ [52 bytes data]
* TLSv1.3 (OUT), TLS handshake, Finished (20):
} [52 bytes data]
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN: server did not agree on a protocol. Uses default.
* Server certificate:
*  subject: C=US; ST=California; L=San Francisco; O=Cloudflare, Inc.; CN=registry.yarnpkg.com
*  start date: Apr 29 02:29:46 2023 GMT
*  expire date: May 13 02:29:46 2023 GMT
*  issuer: C=US; ST=California; O=Zscaler Inc.; OU=Zscaler Inc.; CN=Zscaler Intermediate Root CA (zscalertwo.net) (t)
*  SSL certificate verify result: unable to get local issuer certificate (20), continuing anyway.
* using HTTP/1.x
} [5 bytes data]
> GET /csstype/-/csstype-3.0.8.tgz HTTP/1.1
> Host: registry.yarnpkg.com
> User-Agent: curl/8.0.1-DEV
> Accept: */*
>
{ [5 bytes data]
< HTTP/1.1 200 OK
< Date: Fri, 05 May 2023 02:17:14 GMT
< Content-Type: application/octet-stream
< Content-Length: 175305
< Connection: keep-alive
< CF-Ray: 7c257c694f4253f5-YYZ
< Accept-Ranges: bytes
< Access-Control-Allow-Origin: *
< Age: 1689328
< Cache-Control: public, immutable, max-age=31557600
< ETag: "a06dac7944c631c06fa7509c9095ca08"
< Last-Modified: Mon, 19 Apr 2021 07:35:13 GMT
< Vary: Accept-Encoding
< CF-Cache-Status: HIT
< Server: cloudflare
<
{ [14612 bytes data]
* Connection #0 to host registry.yarnpkg.com left intact
mark@L-R910LPKW:~$

Esta é uma rede corporativa e, portanto, temos o Zscaler atuando como o MITM.

Não entendo por que o curl é "incapaz de obter o certificado do emissor local". Posso executar a mesma linha de comando na máquina host sem problemas:

mark@L-R910LPKW:~$ curl -svo /dev/null https://registry.yarnpkg.com/csstype/-/csstype-3.0.8.tgz
*   Trying 104.16.19.35:443...
* Connected to registry.yarnpkg.com (104.16.19.35) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
*  CAfile: /etc/ssl/certs/ca-certificates.crt
*  CApath: /etc/ssl/certs
* TLSv1.0 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.2 (IN), TLS header, Certificate Status (22):
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [88 bytes data]
* TLSv1.2 (OUT), TLS header, Finished (20):
} [5 bytes data]
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
} [1 bytes data]
* TLSv1.2 (OUT), TLS header, Certificate Status (22):
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.2 (IN), TLS header, Finished (20):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Certificate Status (22):
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [155 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
{ [6 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Certificate (11):
{ [3297 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
{ [264 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Finished (20):
{ [52 bytes data]
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Finished (20):
} [52 bytes data]
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN, server did not agree to a protocol
* Server certificate:
*  subject: C=US; ST=California; L=San Francisco; O=Cloudflare, Inc.; CN=registry.yarnpkg.com
*  start date: Apr 29 02:29:46 2023 GMT
*  expire date: May 13 02:29:46 2023 GMT
*  subjectAltName: host "registry.yarnpkg.com" matched cert's "registry.yarnpkg.com"
*  issuer: C=US; ST=California; O=Zscaler Inc.; OU=Zscaler Inc.; CN=Zscaler Intermediate Root CA (zscalertwo.net) (t)
*  SSL certificate verify ok.
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
} [5 bytes data]
> GET /csstype/-/csstype-3.0.8.tgz HTTP/1.1
> Host: registry.yarnpkg.com
> User-Agent: curl/7.81.0
> Accept: */*
>
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Date: Fri, 05 May 2023 02:25:46 GMT
< Content-Type: application/octet-stream
< Content-Length: 175305
< Connection: keep-alive
< CF-Ray: 7c2588e75bada216-YYZ
< Accept-Ranges: bytes
< Access-Control-Allow-Origin: *
< Age: 1689840
< Cache-Control: public, immutable, max-age=31557600
< ETag: "a06dac7944c631c06fa7509c9095ca08"
< Last-Modified: Mon, 19 Apr 2021 07:35:13 GMT
< Vary: Accept-Encoding
< CF-Cache-Status: HIT
< Server: cloudflare
<
{ [14612 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* TLSv1.2 (IN), TLS header, Supplemental data (23):
{ [5 bytes data]
* Connection #0 to host registry.yarnpkg.com left intact
mark@L-R910LPKW:~$

Por que acho que enrolar no recipiente deve funcionar bem? Porque eu monto todos os mesmos diretórios de certificado do host no contêiner:

  1. /etc/ssl
  2. /usr/local/share/ca-certificates
  3. /usr/share/ca-certificates

Portanto, presumivelmente, o contêiner "vê" os mesmos certificados que o host. Então, por que não funciona?

EDITAR 1

Esta é uma rede corporativa com certificados Zscaler sendo injetados. Se você não estiver em um ambiente semelhante, não poderá reproduzi-lo de forma limpa. Minha pergunta é conceitual - pareço replicar meu ambiente de host no contêiner por meio de várias montagens e, no entanto, o contêiner falha enquanto o host passa.

EDITAR 2

Para experimentar, mudei para o seguinte Dockerfile:

FROM nginxinc/nginx-unprivileged:1.23.3-alpine-slim
USER 0
ARG chip_user_pwd
RUN apk update && \
    apk add --no-cache sudo curl busybox-extras bind-tools nmap-ncat openssl netcat-openbsd openssh git strace && \
    adduser -u 1000 -D chip && \
    echo "chip:$chip_user_pwd" | chpasswd && \
    echo "chip ALL=(ALL) ALL" > /etc/sudoers.d/chip && \
    chgrp -R chip /etc/nginx/conf.d && \
    chmod 0440 /etc/sudoers.d/chip
COPY default.conf.template /etc/nginx/templates/default.conf.template
USER 101

(Eu o uso para solucionar problemas)

A linha de comando para executar o contêiner foi:

docker run --cap-add=SYS_PTRACE -d -v /etc/ssl:/etc/ssl -v /usr/local/share/ca-certificates:/usr/local/share/ca-certificates -v /usr/share/ca-certificates:/usr/share/ca-certificates OurACR.azurecr.io/chip/toolbox sleep 1d

Ele mostra o mesmo comportamento da imagem de ondulação. Corri strace(graças a https://jvns.ca/blog/2020/04/29/why-strace-doesnt-work-in-docker/ pelas instruções) no contêiner e no host.

Ambos lidos em /etc/ssl/certs/ca-certificates.crt : insira a descrição da imagem aqui

No entanto, uma vez terminada a leitura, eles fazem coisas diferentes: insira a descrição da imagem aqui

Por fim, o processo rodando no host chega a ler um dos certificados ZScaler, enquanto o rodando no container faz não sei o quê: insira a descrição da imagem aqui

Onde:

mark@L-R910LPKW:~$ ls -l /etc/ssl/certs/f36a1d00.0
lrwxrwxrwx 1 root root 54 Apr 21 16:46 /etc/ssl/certs/f36a1d00.0 -> 'Zscaler_Intermediate_Root_CA_=zscalertwo.net=_=t=_.pem'
mark@L-R910LPKW:~$

Como é strace contém muito ruído. Adoraria saber como reduzi-lo de maneira significativa.

Esqueci de mencionar. O host carrega /lib/x86_64-linux-gnu/libssl.so.3enquanto o contêiner docker carrega /lib/libssl.so.3. Talvez isso seja significativo.

EDITAR 3

O conselho original a ser usado stracesugeria chamá-lo com -e trace=%file, aqui vamos nós:

janela de encaixe

/ # strace -e trace=%file -f curl -so /dev/null https://dl-cdn.alpinelinux.org/alpine/v3.17/main
execve("/usr/bin/curl", ["curl", "-so", "/dev/null", "https://dl-cdn.alpinelinux.org/a"...], 0x7fff23ab9330 /* 8 vars */) = 0
open("/etc/ld-musl-x86_64.path", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/lib/libcurl.so.4", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/libcurl.so.4", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/lib/libcurl.so.4", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/lib/libz.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/lib/libnghttp2.so.14", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/libnghttp2.so.14", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/lib/libnghttp2.so.14", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/lib/libssl.so.3", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/lib/libcrypto.so.3", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/lib/libbrotlidec.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/libbrotlidec.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/lib/libbrotlidec.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/lib/libbrotlicommon.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/local/lib/libbrotlicommon.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/usr/lib/libbrotlicommon.so.1", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/etc/ssl/openssl.cnf", O_RDONLY|O_LARGEFILE) = 3
open("/root/.curlrc", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)
open("/root/.config/curlrc", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)
open("/etc/passwd", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
open("/root/.curlrc", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)
strace: Process 37 attached
[pid    37] open("/etc/hosts", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 7
[pid    37] open("/etc/resolv.conf", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 7
[pid    37] +++ exited with 0 +++
open("/etc/ssl/certs/ca-certificates.crt", O_RDONLY|O_LARGEFILE) = 6
+++ exited with 60 +++
/ #

hospedar

mark@L-R910LPKW:~$ strace -e trace=%file -f curl -so /dev/null https://dl-cdn.alpinelinux.org/alpine/v3.17/main
execve("/usr/bin/curl", ["curl", "-so", "/dev/null", "https://dl-cdn.alpinelinux.org/a"...], 0x7fff2db4c4b0 /* 30 vars */) = 0
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
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=29679, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libcurl.so.4", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=677656, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libz.so.1", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=108936, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=2216304, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libnghttp2.so.14", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=166256, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libidn2.so.0", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=129096, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/librtmp.so.1", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=121864, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libssh.so.4", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=441944, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpsl.so.5", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=75768, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libssl.so.3", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=667864, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libcrypto.so.3", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=4451632, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libgssapi_krb5.so.2", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=338648, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libldap-2.5.so.0", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=376512, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/liblber-2.5.so.0", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=63992, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libzstd.so.1", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=841808, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libbrotlidec.so.1", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=51512, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libunistring.so.2", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=1743016, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libgnutls.so.30", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=2000320, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libhogweed.so.6", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=289800, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libnettle.so.8", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=281000, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libgmp.so.10", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=526896, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libkrb5.so.3", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=827936, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libk5crypto.so.3", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=182864, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libcom_err.so.2", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=18504, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libkrb5support.so.0", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=52016, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libsasl2.so.2", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=105376, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libbrotlicommon.so.1", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=137560, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libp11-kit.so.0", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=1285888, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libtasn1.so.6", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=92312, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libkeyutils.so.1", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=22600, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libresolv.so.2", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=68552, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libffi.so.8", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=47688, ...}, AT_EMPTY_PATH) = 0
newfstatat(AT_FDCWD, "/etc/gnutls/config", 0x7ffcde3ddb00, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/ssl/openssl.cnf", O_RDONLY) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=12419, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=3048928, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=2996, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_IDENTIFICATION", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=258, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=27002, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_MEASUREMENT", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_MEASUREMENT", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=23, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_TELEPHONE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_TELEPHONE", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=47, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_ADDRESS", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_ADDRESS", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=127, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_NAME", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_NAME", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=62, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_PAPER", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_PAPER", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=34, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_MESSAGES", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_MESSAGES/SYS_LC_MESSAGES", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=48, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_MONETARY", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_MONETARY", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=270, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_COLLATE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_COLLATE", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=1406, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_TIME", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_TIME", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=3360, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_NUMERIC", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_NUMERIC", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=50, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/usr/lib/locale/C.UTF-8/LC_CTYPE", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/locale/C.utf8/LC_CTYPE", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=353616, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/home/mark/.curlrc", O_RDONLY) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/etc/nsswitch.conf", {st_mode=S_IFREG|0644, st_size=510, ...}, 0) = 0
newfstatat(AT_FDCWD, "/", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
openat(AT_FDCWD, "/etc/nsswitch.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=510, ...}, AT_EMPTY_PATH) = 0
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=510, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/etc/passwd", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=1948, ...}, AT_EMPTY_PATH) = 0
openat(AT_FDCWD, "/home/mark/.curlrc", O_RDONLY) = -1 ENOENT (No such file or directory)
strace: Process 577639 attached
[pid 577639] newfstatat(AT_FDCWD, "/etc/nsswitch.conf", {st_mode=S_IFREG|0644, st_size=510, ...}, 0) = 0
[pid 577639] newfstatat(AT_FDCWD, "/etc/resolv.conf", {st_mode=S_IFREG|0644, st_size=96, ...}, 0) = 0
[pid 577639] openat(AT_FDCWD, "/etc/host.conf", O_RDONLY|O_CLOEXEC) = 7
[pid 577639] newfstatat(7, "", {st_mode=S_IFREG|0644, st_size=92, ...}, AT_EMPTY_PATH) = 0
[pid 577639] openat(AT_FDCWD, "/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 7
[pid 577639] newfstatat(7, "", {st_mode=S_IFREG|0644, st_size=96, ...}, AT_EMPTY_PATH) = 0
[pid 577639] newfstatat(7, "", {st_mode=S_IFREG|0644, st_size=96, ...}, AT_EMPTY_PATH) = 0
[pid 577639] openat(AT_FDCWD, "/etc/hosts", O_RDONLY|O_CLOEXEC) = 7
[pid 577639] newfstatat(7, "", {st_mode=S_IFREG|0644, st_size=580, ...}, AT_EMPTY_PATH) = 0
[pid 577639] openat(AT_FDCWD, "/etc/gai.conf", O_RDONLY|O_CLOEXEC) = 7
[pid 577639] newfstatat(7, "", {st_mode=S_IFREG|0644, st_size=2584, ...}, AT_EMPTY_PATH) = 0
[pid 577639] newfstatat(7, "", {st_mode=S_IFREG|0644, st_size=2584, ...}, AT_EMPTY_PATH) = 0
[pid 577639] +++ exited with 0 +++
openat(AT_FDCWD, "/etc/ssl/certs/ca-certificates.crt", O_RDONLY) = 6
newfstatat(6, "", {st_mode=S_IFREG|0644, st_size=190243, ...}, AT_EMPTY_PATH) = 0
newfstatat(AT_FDCWD, "/etc/ssl/certs/f36a1d00.0", {st_mode=S_IFREG|0644, st_size=1537, ...}, 0) = 0
openat(AT_FDCWD, "/etc/ssl/certs/f36a1d00.0", O_RDONLY) = 6
newfstatat(6, "", {st_mode=S_IFREG|0644, st_size=1537, ...}, AT_EMPTY_PATH) = 0
newfstatat(AT_FDCWD, "/etc/ssl/certs/f36a1d00.1", 0x7ffcde3dd2f0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/localtime", O_RDONLY|O_CLOEXEC) = 6
newfstatat(6, "", {st_mode=S_IFREG|0644, st_size=3552, ...}, AT_EMPTY_PATH) = 0
newfstatat(6, "", {st_mode=S_IFREG|0644, st_size=3552, ...}, AT_EMPTY_PATH) = 0
+++ exited with 35 +++
mark@L-R910LPKW:~$
curl
Martin Hope
mark
Asked: 2023-04-24 04:48:38 +0800 CST
  • 12

Por favor, observe:

mark@L-R910LPKW:~$ diff <(echo a) <<<b
diff: missing operand after '/dev/fd/63'
diff: Try 'diff --help' for more information.
mark@L-R910LPKW:~$

Eu sei que <(...)funciona bem:

mark@L-R910LPKW:~$ diff <(echo a) <(echo b)
1c1
< a
---
> b
mark@L-R910LPKW:~$

Eu também sei que <<<funciona bem em geral:

mark@L-R910LPKW:~$ cat <<<a
a
mark@L-R910LPKW:~$

Então, qual é a maneira certa de chamá-lo diff?

bash