Why do I get “/bin/sh: Argument list too long” when passing quoted arguments?

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佛祖请我去吃肉
佛祖请我去吃肉 2020-11-27 18:44

How long can be a command line that can be passed to sh -c \'\'? (in bash and in bourne shell)

The limit is much lower than that from the OS (in case of

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  •  北海茫月
    2020-11-27 19:09

    TL;DR

    A single argument must be shorter than MAX_ARG_STRLEN.

    Analysis

    According to this link:

    And as additional limit since 2.6.23, one argument must not be longer than MAX_ARG_STRLEN (131072). This might become relevant if you generate a long call like "sh -c 'generated with long arguments'".

    This is exactly the "problem" identified by the OP. While the number of arguments allowed may be quite large (see getconf ARG_MAX), when you pass a quoted command to /bin/sh the shell interprets the quoted command as a single string. In the OP's example, it is this single string that exceeds the MAX_ARG_STRLEN limit, not the length of the expanded argument list.

    Implementation Specific

    Argument limits are implementation specific. However, this Linux Journal article suggests several ways to work around them, including increasing system limits. This may not be directly applicable to the OP, but it nonetheless useful in the general case.

    Do Something Else

    The OP's issue isn't actually a real problem. The question is imposing an arbitrary constraint that doesn't solve a real-world problem.

    You can work around this easily enough by using loops. For example, with Bash 4:

    for i in {1..100000}; do /bin/sh -c "/bin/true $i"; done
    

    works just fine. It will certainly be slow, since you're spawning a process on each pass through the loop, but it certainly gets around the command-line limit you're experiencing.

    Describe Your Real Problem

    If a loop doesn't resolve your issue, please update the question to describe the problem you're actually trying to solve using really long argument lists. Exploring arbitrary line-length limits is an academic exercise, and not on-topic for Stack Overflow.

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